5 Speed Manual transmission rebuild

In this thread I plan to highlight the rebuild of my transmission. I had started in my build thread. But, face it when someone is searching for info they don't want to dig so I have decided to make a separate thread here. Every transmission is different, and individual problems may differ. I don't want to make this a how to thread as the FSM is the best reference and lays the path. Mearly show how I did it, and give tips real world tips along the way for those that might have to face this issue in the future. I am just a basic weekend garage mechanic not a transmission pro. My plan is to show that it can be done using a basic garage and inexpensive tools. I still have yet to do this I am not writing about something I have already done. So I hope it works if it doesn't at least you can learn from my mistakes. I'm hoping to perform it over the next several weeks.

Basic outline is as follows.
1. Make a workbench or work surface to hold the transmission while the rebuild is being performed.

2. Fabricate and secure the tools required to disassemble the transmission completely.

3. Complete disassembly and inspection of components.

4. Then of course ordering all the pieces.

5. Reinstalling and testing.

You go on with your bad self...I can't wait to see this...

Made a table $14 in 2x4 lumber, 3/4 plywood section was laying in my attic. Bolted a bench vice right in the middle. Made it in 1 hour nothing special 40 inch height allows me to work on it properly. Cheap fast and sturdy.


I washed my transmission down with my pressure washer. Important to get that Gonemoab utah sand and grime off. Don't want it inside the trans. I washed in the grass as to not stain my driveway with the oil and degreaser. Might as well wash the other pieces. I plan to repaint them before I reinstall them. Won't find that at a trans shop.


Removing the case halves was super easy.


I found that 1st gear was missing engagement teeth so I'm under going the replacement of this gear. Its the furthest in the the main shaft meaning the unit has to be entirely disassembled to pull it off.


First to be removed was the sector shaft case bearing. My craftsman 2 jaw puller made short work of it. Though it was difficult to get a bite on the bearing as the gear is so close.


Next I removed the reverse gear assembly from the main shaft. This required a bit of digging through my tool box to make a puller long enough to reach. Using 3 different pullers bolted together piece by piece. I pulled it off.


That was all the further I got. Need to hunt down a few pullers today to continue with the removal. So far the pieces look pretty good for 167,000 miles. I made a nifty stand out of scrap wood and 1/2 conduit to help keep parts in order.

You're a brave dude, Ben. Remind me to find you when I ever need help fixing things. I am more comfortable than most, but seeing all those gears makes me feel sick..:rawr:

^^^this

LOL I'm not worried about the disassembly trans is already broke. Its the "proper" reassembly that has me haunted.

Silver dude said:

LOL I'm not worried about the disassembly trans is already broke. Its the "proper" reassembly that has me haunted.

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Hence the reason it scares the living daylights out of me to take apart anything complex.

Will you be replacing the clutch while you have the tranny down?

Nah did it about 10,000-15,000 miles prior to my transmission issues. I will replace the pilot bushing though. Cheap insurance.

, Ben

What exactly happened? I have a manual, too...haven't seen many trucks around with it.

NismoFire said:

What exactly happened? I have a manual, too...haven't seen many trucks around with it.

Click to expand...

The trans produced a bearing howl and vibration that seemed especially active at 45mph. I pulled the magnet plug and found gear teeth and metal shavings stuck to the plug.


The broken teeth are engagement teeth.


Which came from the first gear.


Which I believe caused the gear to spin out of balance thus causing the vibration at 45mph. The gear is missing 6 teeth but I only found 4 on the plug. Hoping to discover them in the baulk ring when I tear it down. I think the damage was caused by shifting to 1st while in motion or at speed. I need to make sure to stop then engage 1st. Or it could of happened when my clutch exploded and I drove 1100miles with no clutch to get home. Or offroad it may have popped halfway out while climbing a rough rock face. Really have no way to identify the exact event that caused it as it could of been broken for a long time and took a while to reach the point of terrible vibration.


Your right they are super rare. But, man I love it and wouldn't have it any other way adds so much to the pleasure of the drive. Unfortunately it also makes them super hard to track down used in good condition in a junk yard. I gave up after a week of looking all are high mile transmissions to the tune of $800+ shipping with no clue of the life it had. So I'm hoping to rebuild at or under that figure. But, time will tell crossing my fingers the high dollar parts are ok. In the end I will have a trans with new parts.

Did some more work today. Slipped a huge Snap on puller out of work in my lunch box with a few other random bearing pullers. Haha don't worry I asked my boss if I could borrow them.


Pulling reverse. Note the chunky teeth all reverse gears on cars are straight cut. which is why you get the whrrrrrrrrrr when backing up.


Pulling 5th gear overdrive.


I found the engagement collar for reverse and 5th gear to show a little wear. I'll likely replace it once I order parts.


Now as far as I can go with pullers. So I cleaned up and reorganized Time to buy a press and take it the rest of the way. Hoping to buy one tomorrow.



Ordered a rebuild kit tonight for $375 all the seals, most the bearings, the steels (brass syncros} the usual failure points. I probably didn't need to as it shifted fine before removal. But, piece of mind is a great thing to have. With 167,000miles on this unit and the average manual transmission failure being about 190,000 in our trucks from what I've read. Thought new parts would be nice the main bearings are the most common fail point on these transmissions it has seemed.

I've got 153k on mine....hope it doesn't go anytime soon. Definitely don't have the skill to rebuild it myself.

Get the 20ton press instead of the 12. you will appreciate it. Especially if you get the press break kit from a guy over on pirate. That way you can bend 1/4 inch plate at home.

That and I have a put a pretty nice bend in my 12 ton already.

Yeah I've tried to take good care of my manual tranny...and not hardly any metal on the plug when I changed the gear oil. 170k and counting. Hope to get past 200k and then some. Knock wood.

granitex said:

Get the 20ton press instead of the 12. you will appreciate it. Especially if you get the press break kit from a guy over on pirate. That way you can bend 1/4 inch plate at home.

That and I have a put a pretty nice bend in my 12 ton already.

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Yeah the 20 ton is fully welded not flimsily bolted together. Also giving thought to upgrading the bottle jack to the air over hydraulic for effortless pressing. I scoped them out today but unfortunately they were out of stock and had no idea of when they would be back. Even the warehouse was out in the words of the store clerk.. National shortage! Crap so I went home called the Madison, WI store. Yes sir we have 12 of them in stock. So tomorrow me in the girlfriend are taking the station wagon two hours north to get one and make a day trip out of it. I've seen that brake when I was researching this press last night. Its certainly on the agenda. Would be a great way to make some skid plates. With a 20% coupon should be $150 and some change out the door. Excited about the purchase been needing one for far to long. Lockers, transfer case and even distributor are projects having one in the garage would of been handy.

NMTerras said:

Yeah I've tried to take good care of my manual tranny...and not hardly any metal on the plug when I changed the gear oil. 170k and counting. Hope to get past 200k and then some. Knock wood.

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Yeah thats how the last change interval was with me. Redline mt-90 oil no wear. But crap happens I guess. I've owned two vehicles with this same transmission. A 90's Hardbody and this Xterra. The Hardbody trans bit the dust at 185,000 miles which if you knew how hard that truck was worked its a long time. According to my uncle who owned it before I did. Main bearings blew taking the gears with it. He ended up sourcing a lower mile pathfinder transmission and having it rebuilt. On that rebuilt trans mission I drove past 215,000 miles before I traded it in on the x. I still see that Hardbody around now and then last time towing a boat so I'm sure its still going. If or when you hear noise get it checked out pronto much cheaper then the whole thing exploding.


, Ben

Secured a press. FYI use the 20% coupon if your buying one. Saved me $90 after taxes. More progress in the coming days. Was planning on working on it a bit tonight. But, then realized that I needed to make a saddle to hold the transmission out of wood. It seemed 3AM was a bit late for thoughts of circular saw action in my small subdivision so tomorrow morning. Least I got it unboxed and upright.

Made the cradle to hold the trans in the press from 2x8 scrap lumber. Worked wonderfully with some drywall screws through the case.


Unfortunately, instead of move the bearing on the shaft I heard a POW! The trans case broke... crap. Despite following Nissan's disassembly instructions word for word. Crap happens I guess.


The half decent news is that its only $74 for a new case. So still way under budget on this rebuild.


At least the shafts were freed at this time for further disassembly.


Here is the gear I was after the 1st gear. Note the missing teeth. Bearings looked ok didn't find the two other missing teeth. Perhaps they are till in the case. Engagement ring was flawless.


Removing the bearing that broke the case. Seemed to slide right off like it should have.


More pressing resulted in removal of all the parts.


Shafts are stripped down all parts are ready to be fully inspected. Case bearings need to be driven out. After that start browsing the parts catalogs and order parts.

You are the king, sir!

I keep thinking about picking up a pnumatic bottle jack, if for nothing else just to make it easier to position items in the press.

Yeah its easy enough to remove from the press assembly that you could use it like a normal jack. Then when you need it slip it in place. I does get irritating when the press rod is about 2" off the part and you have to pump the low ratio jack about 50 hundred times. But, then how often do you really use the press I guess. Maybe a little more time makes for a quality job. Though it would be nice to hide behind the truck with the air hose using the truck as a blast shield. Hahaha presses can be scary.

Ben

Cajones! Jeebus.

Here is some of the parts that I've felt warranted replacement. Not because it was absolutely needed. But, because I want to stretch more life out of my transmission. I plan to have the Xterra a long time so a strong investment now could pay off later. Some may laugh at how small the wear on the items is. But, it will put my mind at ease when I go back together with it knowing I didn't put a fault part back inside.

I also am replacing the 1st gear shift fork (not pictured) tossed it in last minute.


Some of the snap rings are tweaked from removal so I'm going to replace the badly tweaked ones. As cheap as they are $1 or 2 at the most I feel it's a good idea.


The shifting inserts were worn quite heavily. They are not supposed to have lines down the middle of them. Replacing all of them.


The reverse idler thrust washer had worn a groove. Though small and probably fine at $5 to replace it and tighten the idler back up I feel it was worth it. Again just to justify my sanity.


Both aluminum shift forks had groove where the ring had been working at for a while. I figured this could make the shifting sloppy. Or perhaps allow the ring to half engage stripping the gears like what happened to first gear.


3rd / 4th shift fork had wear at the top. I'm guessing it became worn out enough to rub at the top.


Then of course the stripped 1st gear, the worn reverse engagement ring, section of case that my press broke are all being replaced. The more time goes on its looking closer to the $800 mark little under. But, I can assure you that this is still cheaper then taking it somewhere to get rebuilt, as well as being far more in depth with this rebuild. Because unlike the trans repair shop, getting it out the door as fast as possible and saving money are not my top priorities.

Ordering parts and waiting for their arrival.

The rebuild kit came today. No time to really look it over but they sure could of packaged it a little better. Kinda disappointed to see it loose slamming around in the box. Bearings full of paper fiber.

You're not done yet? You sure seem to be taking your time. I've taken apart some complicated stuff before but what you're doing scares the heck out of me. I know it just boils down to put it back together the way you took it apart but I see lots and lots of pieces. Big giant KUDOS to you!

You will appreciate all the extra effort you're putting into when you go to shift it and its like butter every time, plus the piece of mind knowing you did it right.

Finally finding time to go back together with it. Hope to have it together by this weekend for some offroading next week.


Removed the dowel pins from the damaged case section.


Ahhhh fresh new OEM bearings...


Using a brass drift I hammered the new bearing into the new case section.


Unsure of how to remove the shift rail bearing without damage. I carefully cut the bad case apart to remove it.


Then put it in the new case after cleaning..


I had picked up some Redline assembly lube. So far I love this stuff. Its sticky and slick as snot. Frees friction. Best of all its compatible with the Redline MT-90 which I will be installing later. Here is some installed on the new counter shaft thrust bearing.


Pressed a new bearing and snap ring onto the input shaft. The stock thickness ring worked perfectly.


I built up the 3-4 gear synchronizer for install onto the main shaft at a later date. New springs, new inserts, lubed with assembly lube, bagged to prevent dust and grit. At this point I'm wishing I took more pictures to reference directions of parts. I'm finding the manual to be very brief and missing details.


More later...

everything seems to be coming along well as can be expected, I am glad that you can take your time and do it rite instead of rushing through it just to get done.

granitex said:

everything seems to be coming along well as can be expected, I am glad that you can take your time and do it rite instead of rushing through it just to get done.

Click to expand...

Yeah after this I'll either be looking at a spare car or a motorcycle and demote the Xterra to project truck, camping rig, that I can drive if I feel like it. The spare car I'm borrowing is proving to be so nice as I can take my time. To double the fuel economy, have a ride that zips though downtown traffic, while reducing the wear on my pride and joy xterra well lets just say it sounds like a great idea.

The manual is proving to be incorrect in some areas and completely neglectful in others. Perhaps the hardest part of this rebuild is jut confirming to yourself the correct orientation of parts. I'm glad I took pictures as the pictures can't lie.

Installed the 3-4 gear syncros.


After using the press I installed the snap ring. Its starting to come back together. The big snap ring worked well to prevent it from rolling off the table.


Made sure to prelube all the components I don't want a dry start. The trans could easily bind otherwise. I'd imagine the trans probably wouldn't turn without prelube as there is so many friction points.


More pressing the syncro assemblies on to the shaft.


Ready to put into the case half.

I installed the counter shaft in the transmission case and made sure I didn't need thicker thrust washers. Fortunately, after a bit of measuring with the dial indicator it was well within spec.


I installed the spacer plate in the bench vice. I had made some soft jaws for the vice from 1" aluminum angle as to not scratch the spacer plate.


I then slid the main shaft into the spacer plate.


Lubed up the input shaft and made sure the syncro was in place.


Slid the input over the main shaft and began fitting the counter shaft into place.


Putting the 2 shafts thru the spacer plate was a bit of work. This required perfect alignment and strong soft hammer smacks to spacer plate. Nissan had a special tool the pryed the main shaft thru the bearing. I had the resources to make such a tool. However, with strong hits from a dead blow hammer I managed to seat both shafts easily.


Looking more complete.


Stopped at the overdrive spacer. Need to get a BFH and swing it at this pipe I bought and its 4am so later this afternoon I'll use this pipe to loudly drive it onto the shaft with a hammer.

This is my favorite thread. period. Looking good!

glad to see it coming back together, keep up the good work.

Thanks fellas feels great to be going back together with this. I had the day off work despite having to run a bunch of errands I managed to get a good chunk done today. By far the most struggle and brainpower invested today.

Pounding these items onto the shafts were a real bear. I swung my 3 pound sledge hammer at them. The issue was that the shafts would simply slide though the plate on each hit.


But, eventually it made its way down the shaft and I mounted the 5th gear on the counter shaft.


Swapped the brass syncro new on the right.


Pounded in the friction hub part that fits the syncro.


Lubed it up real good and dropped the ring and syncro down on it.


Unfortunately, one of the syncro's included in the rebuild kit was to small. So I just reused the original. Not great but better then waiting 2 more weeks.


Mounted reverse gear.


Lubed up the reverse idler shaft. Reverse is the only gear with a idler gear. The idler gear is what reverses the rotation.


This is where it got real complex. The C ring wouldn't fit to lock the shaft in place.


I equated it to the 5th gear not being seated against the bearing properly. Remember I was hitting it with my sledge and shaft was moving making it hard to drive the gears in? Well I thought this was what was causing the additional space preventing the C rings from fitting.


So I made this pusher thing to put load on the shaft preventing the shaft from sliding through the spacer plate while I hammered hard with a brass drift. I got the gear firmly seated.


This helped but it still wasn't enough to seat the C-rings. I did not see how I could remove any more space from the shaft. Everything was seated correctly. Then I found out nissan sells 8 different thicknesses of c rings as so you can shim the unit. Mine were middle of the pack 2.91mm or so thick. I decided I needed 2.63mm after careful measuring which was available. I'm equating the tighter fit do to the new bearings possibly being a hair wider. So I thought and I thought and I figured I would just cut the sleeve to fit as it would do the same exact thing and I wouldn't have to order pay money and wait. So I chucked the spacer in my lathe.


Removed the proper amount.




Perfect fit, I had to hammer the rings in place.


Hammered and clipped the bearing in for the counter shaft.


Slid it back in the bench vice for installation of the shift forks.


5th gear shift fork was first.


The rest also slid together.


Ready to go back in the case.


I prepped the cases for the install by removing the old gasket material.


As well as spraying brake clean to remove the sludge and dirt that fell in.


I began to replace the front shaft seal. It came out easily with a small prybar.


At this time a friend stopped by with a few beers so we quickly applied gray RTV and slapped the cases on.


I installed the necessary C clips and lubed the bearings before placing the gasket and cover on.


My friend was still hanging out so we applied gray rtv the back of the trans.


Mounted the transfer case and breather lines.



Thats a far as I got tonight. Still more to come. I have wiring to sort out on the transfer case. Pilot bushing in the flywheel. Throw out bearing and the shifter linkage. So far I can say it looks real good.

I just read this thread from top to bottom. Wow... I give you much praise for first making the decision to do this yourself and secondly sticking with it. Just goes to show trust in yourself, proper research a little patience and anything can be done. Great thread... REP POINTS for sure.

Well I tried to give rep points but it stopped me...

Holy moly, that freaks me out just looking through the pics!

Well I got it in the truck and I can say with honesty that it shifts better or as good as the day I bought it. It shifts verrrrry smoothly gear to gear. A friend and I started at midnight got it in and driving by 6am. Then left at noon the next day for a 700 mile round trip to michigan to offroad and mountain bike.

On to the install story...

The transfer case has had these wires ripped for a while. I had patched them up but soldering over head in a narrow area under the truck made for pretty crummy work. So when it broke again I figured it was time to figure a solution. The wires were brittle and never really absorbed solder well. Probably do to the dry baking heat of the transmission.



So I replaced the connector and brittle wire with a fresh piece of wire. I didn't see a need to retain the connector as I don't see myself replacing these switches anytime soon. They are steel threaded into aluminum. Disimilar metals corrode making replacement impossible.



Being that the rubber boots were long gone and I needed this to be sealed. As well as help provide stress relief for the wires preventing it from cracking. I covered the switch and part of the wires with clear silicone.



Not the prettiest but effective.



When it came to the pilot bushing I had bought this special tool for $5. It treads into the bronze sleeve bushing. Then with a grease gun you hydraulicly force the sleeve out of the crank shaft. Great concept... terrible execution. First problem, I had to cut it shorter to not bottom out in the hole. Second problem, it oozed grease everywhere and never removed the bushing.



Soooo I thought and I thought being 2am at this point my resources were limited. So I went to the lathe and made this remover installer tool. Hey it was boring work so I had to make it fun.



How this works is much like a piston. You pack the cavity and bushing with grease. Then smack it with a hammer. Slam! The grease forces the bushing right out of the crankshaft. Then flip the tool over and drive the new one in.



Going in



Then I cleaned all the grease off and put the clutch and pressure plate back in place. Pulled the alignment tool greased the bushing and splines.



Installed the early pathfinder transfer case skid plate. Sure it might not do much, but it don't weigh much and it helps a little.



She has wheels and a piece of beer carton to prevent stuff from falling inside.



In she goes.



Noticing that my shift knobs were quite worn to a shine. I chose some new Sickspeed shift knobs. At a little over 2" ball diameter shifting comfort has improved greatly. Being that they are plastic you don't have to deal with temperature extremes when its hot or cold. I bought the matching knob for the transfer case as well.



Back in action

I'd say you graduated form the McGiver school of Giterdun with honors!!!. lol Now all you need to do is a writeup for us A/T guys.

x2 on that. I'm pretty sure mine could use some rebuild love.

Standing ovation
:kewl: