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Transmission Rebuild Time

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1 minute ago, datzenmike said:

OK I guess the last post with pictures was not showing.

 

rSL24ZS.jpg

 

This looks normal. It's torn from removal.

 

You can degrease the front and rear cases in a cleaning tank. I would just uses a citrus de greaser and power wash at home.

 

81wsC4k2rmL._SX425_.jpg

 

 

I got mine for under $4 maybe it was mislabeled? Goddamn it cleans hands really well. Spray it on wait 10 min power wash.

 

The chewed up leading edges on that is the reverse gear. It might whine while reversing but who cares?


Thanks for the tip, I have a pressure washer so I'll probably just do that.

It never made any noise in reverse, but it wouldn't go into reverse gear some times, I'm guessing whenever this tooth was the one in line. I never need to go into reverse in a hurry so it never bothered me to just try it again but I figured I would fix as much as I can while I had it all open.

The imgur link didnt work?

 

What am I looking for in here that is making it pop out of 5th? It felt like it would go into gear but then it would be pushed back out as soon as I let the clutch out. I remember something about a king nut or ???

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The pictures are there now but when I started to write the post they weren't. No worries.

 

There is a reverse check sleeve that prevents shifting from 5th directly down into reverse. You could use a grinder and just clean them up a little that might help getting into reverse. It just might be that the teeth hit just the right way and can't mesh or slide together... I just let the clutch out and in to spin them and try again. The chewed up gears are from not being stopped when shifting into reverse or if in neutral with clutch pedal up and then deciding to back up not giving the gears 2 seconds to slow down after the pedal is depressed. The gear oil will slow the gears quite fast.

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10 minutes ago, datzenmike said:

The pictures are there now but when I started to write the post they weren't. No worries.

 

There is a reverse check sleeve that prevents shifting from 5th directly down into reverse. You could use a grinder and just clean them up a little that might help getting into reverse. It just might be that the teeth hit just the right way and can't mesh or slide together... I just let the clutch out and in to spin them and try again. The chewed up gears are from not being stopped when shifting into reverse or if in neutral with clutch pedal up and then deciding to back up not giving the gears 2 seconds to slow down after the pedal is depressed. The gear oil will slow the gears quite fast.

That's what I was doing, I'll see if I cant smooth it up a bit to see if that helps. I am more worried about my 5th gear slipping out, don't like the idea of running it at 4kRPM every time I wanna take the freeway.

Thanks for all the help, is really exciting to finally get into this.

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Oh yeah 5th jumping out of gear.

 

Maybe it's this... Look on the main shaft for the (aptly named) main shaft nut. Pictured below at the bottom just behind the speedometer worm gear. Some are farther back.

 

 

0FKeQJ9.jpg

 

It has a thin flange that is staked into a dimple on the main shaft to prevent it loosening. Older models didn't have  this and it would back off and loose 5th. Pry up the staking and tighten the nut if you can. Don't worry you can't hurt anything.. it's supposed to be 100-120 ft lbs. If you manage to tighten it don't forget to stake that collar.

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On 9/8/2019 at 8:44 PM, datzenmike said:

Oh yeah 5th jumping out of gear.

 

Maybe it's this... Look on the main shaft for the (aptly named) main shaft nut. Pictured below at the bottom just behind the speedometer worm gear. Some are farther back.

 

It has a thin flange that is staked into a dimple on the main shaft to prevent it loosening. Older models didn't have  this and it would back off and loose 5th. Pry up the staking and tighten the nut if you can. Don't worry you can't hurt anything.. it's supposed to be 100-120 ft lbs. If you manage to tighten it don't forget to stake that collar.

Hell yeah thanks!

I ordered the kit, shopping around for pullers. That nut is staked but it has some play so its definitely not 100ft/lbs tight.

Whats a good way to pry up the staking?
What goop did they use to seal this?

 

Edited by igotatruck
didn need the pic

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I used a small screw driver and pried it up, anything will do that doesn't break. I was able to turn about 1/8 turn tighter then staked in the new position. I doubt this is the problem as it would have to back off a lot more than this.

 

I used Permatex  Ultra Gray https://www.permatex.com/products/gasketing/ultra-series-gasket-makers/permatex-ultra-grey-rigid-high-torque-rtv-silicone-gasket-maker-2/

 

 I set the front case on 2x4s and lower the gears down onto it. Nothing special needed.

 

The tail case is a bitch to line up and get together, then check that all the gears are there to put sealer on first. I confirm the shifter is selecting all the gears and it's not jammed in 5th or something. Then I pry apart 1/4" and carefully squeeze a small amount of sealer into the crack and allow the tail, case to settle under it's own weight, wipe away excess that squeezes out, put the bolts through the adapter plate into the front case finger tight, wait one hour then torque the bolts.

 

Naturally preparation is everything all joining surfaces must be clean and de-greased.

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12 hours ago, datzenmike said:

. I doubt this is the problem as it would have to back off a lot more than this.

Thanks again!

What else could cause this if not this nut?

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Assembly is only really possible if the trans is in neutral. Otherwise the striking rod won't be able to find its home.

 

Be very careful when tightening the nut. End play in the gear is sometimes caused by a worn thrust washer and sometimes tightening the nut can cause the end play to go away and bind the gears. If it is run this way, the gear will weld itself to the gear hub. So after you tighten the nut, double check that the gear spins freely with no binding.

 

Mike - did you just admit to using RTV? I thought it was unprofessional to use RTV.

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icon-lol.gificon-lol.gif

 

Well there is no gasket involved here so the correct sealer is needed. I am simply using what the factory used or equivalent. FWIW no where on the Ultra Gray does it say RTV icon-lol.gif 

 

For the cover plate on the front, I cut my own gasket........ and put it on DRY.

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Tomato - tomato.

 

Some of them used gaskets on the mid plate.

 

Leaving the front gasket off actually helps shorten the shift stops. Even the .050" of the gasket helps keep the rails from "over-shifting" and getting stuck in a gear.

 

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None of the 71Bs I've had apart L, Z, SD, and CA do and I see no part numbers for any other transmission with an adapter plate.

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59 minutes ago, Stoffregen Motorsports said:

Edit - leaving the gasket off the front plate shortens the shift stops.

I think im gonna do it as stock as possible, if it lasts as long as the first time, it will probably outlive me.

 

Please excuse my ignorance in the following questions:

How do i know if it is jammed in 5th?

Should the shifting rods move freely by hand? The shafts spin but I cant simulate a gear change how it is now, all the rods that accept the striking lever (?) will not slide around.

 

Also what else could make it pop out of 5th since it sounds like this nut has not backed off a substancial amount?

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12 hours ago, datzenmike said:

None of the 71Bs I've had apart L, Z, SD, and CA do and I see no part numbers for any other transmission with an adapter plate.

 

Mine had no gasket on the middle plate, just the front one.

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On 9/13/2019 at 9:00 AM, igotatruck said:

I think im gonna do it as stock as possible, if it lasts as long as the first time, it will probably outlive me.

 

Please excuse my ignorance in the following questions:

How do i know if it is jammed in 5th?

Should the shifting rods move freely by hand? The shafts spin but I cant simulate a gear change how it is now, all the rods that accept the striking lever (?) will not slide around.

 

Also what else could make it pop out of 5th since it sounds like this nut has not backed off a substancial amount?

Leaving the gasket off the front plate isn't a hi-performance mod. It's one that you do to an old trans that has some wear.

 

Jammed in 5th - are you referring to my comment about tightening the nut? If yes, then it will be obvious. With the trans in neutral, all gears should spin freely on the shaft. If after you tighten the nut, it does not spin freely, then the gear is binding on the shaft.

 

If you're referring to the shift rods being jammed, no, they do not shift by hand. There are spring loaded detents on the shift rods and on the gear hubs, so shifting it with the cases off is usually done with a big screwdriver.

 

Popping out of fifth can have multiple causes, but the main culprits are usually the nut being loose and the roll pin in the shift rod being broken. Oh, yeah, inspect all roll pins while you have it apart. If any are broken, replace them, either with OEM style single roll pins, or with double roll pins, which are a HD version of the OEM units.

Edited by Stoffregen Motorsports
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11 hours ago, Stoffregen Motorsports said:

Edit - leaving the gasket off the front plate shortens the shift stops.

 

But then I'd have to use a sealer. icon-lol.gif

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On 9/13/2019 at 9:07 AM, Stoffregen Motorsports said:

 

Popping out of fifth can have multiple causes, but the main culprits are usually the nut being loose and the roll pin in the shift rod being broken. Oh, yeah, inspect all roll pins while you have it apart. If any are broken, replace them, either with OEM style single roll pins, or with double roll pins, which are a HD version of the OEM units.

 

Okay, got it shifting with the screwdriver, it spins freely in neutral at the moment.

The roll pins seem fine externally, would they be broken inside? My book calls them "retaining pins".

usEiA5A.jpg

 

Here is a video of the nut showing how much play and thread is left.

https://i.imgur.com/vsyINrh.mp4

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Not much, about the same as my 5speed when adjusted.

 

Work the 5th/rev shift rod back and forth and look for something not right. 

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17 hours ago, datzenmike said:

 

 

Work the 5th/rev shift rod back and forth and look for something not right. 

This will help expose a broken roll pin. They can appear good, but be broken inside though, and still grab enough to move the shift rod. So your judgement is important there.

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I assume reverse still works and it's on the same rod. This is the least shifted and used gear so wtf???

 

 5th/reverse is on the mainshaft to the rear of the adapter plate check the bearing in the adapter plate and the one to the rear behind the speedo worm gear. If bad the mainshaft may be wobbly/unstable. The rear one is easy to see and spin. The adapter plate is more a visual check fro broken bearing cage. Move the mainshaft at right angles to see if loose/sloppy.

 

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On 8/30/2019 at 11:27 AM, bottomwatcher said:

I am curious about the country of origin on those bearings. If you buy the kit let us know. 

Okay so they are all this NACHI brand from Japan with the exception of this one with the blue grease marked "6204 2RS NR"

ZzfDY2B.jpg

The syncros and smaller bearings have no markings on them.

 

On 9/16/2019 at 5:04 PM, datzenmike said:

I assume reverse still works and it's on the same rod. This is the least shifted and used gear so wtf???

 

 5th/reverse is on the mainshaft to the rear of the adapter plate check the bearing in the adapter plate and the one to the rear behind the speedo worm gear. If bad the mainshaft may be wobbly/unstable. The rear one is easy to see and spin. The adapter plate is more a visual check fro broken bearing cage. Move the mainshaft at right angles to see if loose/sloppy.

 

 

Yeah the reverse worked, my initial test made it seem like there was some play in the main shaft, but I will keep futzing with it tomorrow.

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