John V

Running late for an apt. but wanted to post some pics of my tranny rebuild process.

EDIT: don't know what happened to the pics so hopefully they posted a few threads down.

atb

Wow, John, you must have really been running late.

Shark Attack

ahh yeah... i am getting ready to do this,, can you please finish the post when you get back?

John V

I don't know what happened... I checked the last post real quick as I ran out the door and the images were a bit large but they were there. Anyway, here's a repost (It's after 1 AM & I'm beat).

A few tips to keep all the info in one spot:

1) dropping the box was straight forward. The only stumble I had was that I didn't realize the torque tube to tranny bolts were not just the 4 obvious corners... there's 2 additional bolts just below the shifter rod up on top of the torque tube (tough to see from below).

2) Getting the covers off the tranny and removing the diff was easy. Getting the pins out of the shift selector rods was not. Like Brandon commented in his tranny thread, these pins require quite a bit of force to remove.

3) Looking at the dog teeth (pcs below), they don't look that bad to me... I'll get a better look once I get deeper.

4) My reverse gear worked fine but the teeth look like they should be causing some trouble (see pic)... not sure what I'm going to do there... suggesttions?

5) I was worried that I wouldn't be able to identify why 1,2,3 syncros were't working like 4 & 5... I think I can see why now. When engaging 4 & 5 shift sleeves, the sleeve slides easily (with detent removed) until the syncro starts to engage -where some friction becomes evident. At that point (onset of syncro friction), there is about 2-3mm of additional travel required of the sleeve before the dog teeth start to mesh with the sleeve. In gears 1,2 & 3, the amount of clearance between the dog teeth and shift sleeve is much less where the syncros first produce friction. About 1/2 as much... I think this reduced clearance (likely caused by syncro wear) is insufficient to allow the gears to syncronize before the dog teeth and shift sleeve meet.... At least I hope that's what's going on.



Diff removal step 1 - center bolt removed - slight jerk required to pull shaft.


Diff removal step 2- gentle even prying using cast in ears reguired to extract o-ring.


Reverse gear teeth


!st gear dog teeth


2nd gear dog teeth


3rd gear dog teeth

heinrich

keep em coming, living vicariously

Garth S

The reverse gear has no syncro, so will continue to work fine if engaged with care - the damage is usually caused by many missed shifts to 2nd, or a newbie looking for 1st.

Peter F

I thought you posted this in another thread?
Anyway keep pictures coming.

Thanks/Peter

danglerb

Makes me feel 5 years old, pretty pictures and I don't have a clue what they mean.

BC

NICE PICS!

My reverse is exactly the same. In the last few posts on my 78 5spd thread I mentioned that I was concerned about he reverse gears, then realized that the reverse doesn't have a synchro. So the rounded teeth are from either Porsche making that rough ramp, or us jamming these cars into reverse, which is something I am fully guilty of.

The second to last pic shows what I am seeing in increasing propensity on 1,2, and then three successively. The rounding of the dog teeth. I think that allows the synchros to have to do more work? Then they wear out? I don't know.

John V

To continue on - today posed some challenges. Keep in mind this is my first tranny rebuild but I'm fairly mechanically inclined, an engineer and machinist. I have a new found respect for those of you that have done this on your own. It was tough to take pictures in process as some of this requires heavy persuation.

In stripping the case down, I ran into a few issues during the process.

Counter shaft- after the selector fork removal, the counter shaft must be dropped by removing the lay shaft . The counter shaft stays in the box - the layshaft pulls out to allow the countershaft to drop , hopefully it drops down to the bottom (mine didn't as I found out later. Photo - clip removed shaft tapped out from diff end and extracted at input end:



Next comes removing the input shaft end. I struggled badly with this. The bearing cap, which is supposed to just turn and pull off once the large clip is removed, wouldn't budge. I broke a chip off it trying to pry it as there is nothing to grab by. I ended up making a puller in my machine shop that went into the input shaft spline and was clamped down by the compression collar. I was then able to exract the input shaft (with bearing cap in tow) out but only after struggling to find out that the counter shaft didn't drop down far enough to clear 5th gear dog teeth. The tool is in the picture as well as the chip from the bearing cap. This step took me about 2 hours between trying to figure it out, making the tool and finally getting this thing extracted. 5th gear syncro pieces fall out during this step.



Next comes the removing the reverse gear. This is fairly easy. You remove the pinion shaft retainer bolts, spin (clock) the retainer and shims so that the reverse gear shaft lines up with a cut slot in the reatiner, and pull the shaft using a screw (the axel shaft center bolts work great for this). I used a simple claw hammer on the bolt to pry it out.



With the reverse gear shaft out, once again make sure the counter shaft is down at the bottom of the case and not catching on the pinion shaft. Also make sure the small reverse gear is out of the way and carefully try sliding the pinion shaft out. This is harder than it sounds because the assembly is heavy and bearing bushing is a very precise fit in the bore. Any misalignment causes the whole assembly to bind. With some careful jostling, including standing up the case and wiggleing the shaft end, this does come out without a puller (at least mine did).



Here's the whole pinion shaft.



Once the pinion sfaft is out, you can get a good look at the counter shaft and reverse gear which just lift out.



This is the the lay shaft, counter shaft, reverse shaft and reverse gear.



More to come as I go. Comments, tips or questions welcome.

BC

This is all looking very familiar John.

I feel so inadequate that I just did this over christmas and took two pics.

John V

Brendan - how did your input shaft come out???? That part really kicked my ***! I can't figure out how someone would do that without a machine shop!


BTW- if anyone knows of a reasonable LSD unit, kindly let me know.

BC

Yes, I was reading your comments about "going to your machine shop" and making that push block. Really Cool.

I took 5th AND fourth out of the trans with the main shaft still in situ. I got the non-threaded reverse shaft out, and with all of those gears out of the way from the bottom, I kind of put padding on the back bottom there where the main will slide through - knowing me it was going to fall on a finger or something. It fell out after some persuation.

But I just realised that you mean the input shaft where its out side the case at the front.

You may want to close your eyes - but I have two 78 transmissions, and I just wanted the thing apart, and could use the other units input. So pried on that female spine piece with a big bar, and hammered on it. Seriously.

Don't shoot me, but I didn't have an option on Christmas eve.

BC

I have one. Two actually. So you can have one of them when you are ready for a couple hundred - which is what I bought another one for.

Then you can take it apart and buy new grab disks for it and make it all new and nice.

John V

Brendan - deal.

let me know how to pay you and get it shipped.