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Discussion Starter · #1 ·
I've never opened a transmission before but plan on at least splitting her open to see if anything is horribly wrong. I've rebuilt a few motors and have decent shopcraft where that is concerned, but not sure what works well to support the tranny and its parts while under the knife. Any inspiration pics?

One of my shop resolutions has been to spend a bit more time on workplace setup and not to do anything else on 2x4s sitting on the floor. Like how I just drifted out the old mount...
 

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I throw a piece of cardboard on my woodworking bench for disassembly/ reassembly. The center section of my transaxles clamps very nicely in a lead jawed vice for the actual "surgery". I recommend lots of light, a wide open flat table or bench to lay out the parts (in order!), a good diagram and a REALLY god air of snap ring pliers.
 

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Discussion Starter · #3 ·
Thanks for the tips. Luckily I just bought a great set of Chan-L-Lock snap ring pliers... but my vise setup may be lacking.

Did you use a puller or press to disassemble the main shaft?
 

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Nothing fancy

After I drop the gearbox assembly onto the tranny jack, and slide it out from under the car, I secure the strap, raise the jack, and roll the whole thing onto a drip pan. That's where I remove the bell housing, rear cover and shift rod pressure balls and springs.

Then I can take just the central gearbox clam shell case over to my old towel-covered workbench where I have positioned a couple of 2x4's to "cradle" it and keep it from tipping during dis-assembly.

Aside from a Proto J4038 11-inch 3-arm puller, an OTC 1123 bearing splitter, and a pair of Lang #75 snap ring pliers, I take advantage of a large old hydraulic press at work.

The only other tool I invested in was a used deep fryer I found on craigslist for $20. I use that to heat the parts to 302F during assembly.
 

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Discussion Starter · #7 ·
Can you tell me which operations you use the puller vs bearing splitter & press for? Reading Braden's book it seems like a puller will do the trick for all disassembly tasks. Am I missing something? I have a 12t press. Debating what the best tools to acquire are, and 3-arm pullers seem to be quite useful.

If the whole process can be done with a well positioned bearing splitter and a none too fancy press, that works too.
 

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For the output/mainshaft, I was able to remove everything except the 2nd and 3rd gears (and their respective synchro hubs) with just the puller (first photo).

The 2nd and 3rd gears are too close to each other to allow the puller arms to get a reasonable purchase between them, so I needed to use the bearing splitter and the press to separate them a little. I placed the flat side of the splitter up against 2nd gear (because it has a slightly larger O.D. than 3rd) and then used the press as shown in the second photo.

Once I got about 1/4" space between the two gears, I stopped pressing because I could then get a grab on the hubs to remove them separately.

The reason I didn't just press the gear and hub off together, is because I was concerned that the crescent hub keys (lodged in the shaft slots) would scratch the inner surface of the gear bushing as it passed over them. So I just separated the gears enough to be able to pull the hubs off by themselves. I could then remove the hub keys before I slid the gears off the mainshaft.

As it turned out, all my concern was for naught because I found the bushings to be worn out of tolerance so I needed to replace them anyway. But that's a whole other story.
 

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Discussion Starter · #9 ·
Thanks again. Issues of the crescent key aside, do you think the bearing splitter and press combo could do the entire job by itself?
 

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Thanks again. Issues of the crescent key aside, do you think the bearing splitter and press combo could do the entire job by itself?
I was about to ask the exact same question....i have a press already and have been pondering the benefit of having some OE style plates made up versus the bearing splitter.
 

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Bearing splitter and press should work fine

Thanks again. Issues of the crescent key aside, do you think the bearing splitter and press combo could do the entire job by itself?
r-mm:

When I first started this project, I didn't know how sturdy the hubs were, or how tightly they were pressed onto the output/mainshaft. I was concerned that if I put a lot of pressure on just the outer tripod tips, I might bend or break them. So I wanted to get a grip on the hub as close to the shaft as possible. That's why I chose to use the 3-arm puller. The first photo below shows how the puller arms afforded a nice grip on the inner web of the 5th gear hub.

However after pulling off the 5th gear hub with the puller, and seeing how well it was constructed in relation to how tight it was on the shaft, I decided that I using a bearing splitter on the hub tips alone would not be a problem. The only concern is making sure each of the 3 hub ears are contacting a surface on the splitter when you start pressing.

The second photo shows how I used the puller on the reverse gear, but I'm sure the bearing splitter would have fit just fine, and provided enough surface contact to sufficiently distribute the stress if I had chosen to use the press on that gear too.

I was about to ask the exact same question....i have a press already and have been pondering the benefit of having some OE style plates made up versus the bearing splitter.
1750GT:

Per my comments above, you should be just fine doing the whole mainshaft dis-assembly with a suitable bearing splitter and press.

But if you opt to purchase a custom built set of the OEM plates (S, S1 & S2), could you share with me the price you are quoted, and contact info for your machine shop? I would like to obtain a set for future use myself (if the price is reasonable).
 

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Discussion Starter · #12 ·
Edward - thanks very much, this is an excellent explanation, exactly the type of knowledge that's hard to glean from books alone.

A friend offered to turn some OE style S1, S2, S3 plates for me, but the cost of the big stock needed and the fact that I don't want to take up too much of his time makes me think a bearing splitter is the way I'll go. If I were to have him make them, he could make them on his router if they are aluminium rather than steel. If they must be steel he suggested I buy some plate and he can rough them out with a plasma cutter then chuck them, turn them and split them with a band saw.
 

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Edward - thanks very much, this is an excellent explanation, exactly the type of knowledge that's hard to glean from books alone.

A friend offered to turn some OE style S1, S2, S3 plates for me, but the cost of the big stock needed and the fact that I don't want to take up too much of his time makes me think a bearing splitter is the way I'll go. If I were to have him make them, he could make them on his router if they are aluminium rather than steel. If they must be steel he suggested I buy some plate and he can rough them out with a plasma cutter then chuck them, turn them and split them with a band saw.
Hi r-mm,

I like the idea of aluminum because it is softer than the tool steel (of the gearbox parts), so there would be no chance of scratching, marring or damaging the precious gear or bearing surfaces if the press plates were constructed of aluminum.

Unfortunately, with the high pressure involved, and the relatively thin plate features (0.14") that are required to get between some of the closely-placed components on the shaft, I think steel is the only viable option, at least for the S2 plate.
 

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Discussion Starter · #14 ·
I figured I'd start with small investment and see how things go. This guy was $25 from Harbor Freight and fits nicely around reverse. I'm sure the fit for the 2nd/3rd will be a bit more critical, but I'll let you guys know what I find.
 

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I figured I'd start with small investment and see how things go. This guy was $25 from Harbor Freight and fits nicely around reverse. I'm sure the fit for the 2nd/3rd will be a bit more critical, but I'll let you guys know what I find.
Good stuff r-mm. You are on your way. But I hope you plan on placing the flat sides of the splitter plates up against the reverse gear before using it to press the reverse gear and 5th gear hub off together. The curved sides of the splitter jaws won't distribute the pressure across as much surface area as the flat sides will.
 

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Thanks for the tips. Luckily I just bought a great set of Chan-L-Lock snap ring pliers... but my vise setup may be lacking.
This is the set of vise jaw adapters that I use:

Olympia Tools 38-695 2 Pack Magnetic Vise Jaw - - Amazon.com

The nylon and aluminum materials won't damage the surfaces of the steel gearbox parts, and the pre-formed horizontal and vertical slots work great for holding the shafts.

In addition, I wouldn't have been able to deal with the heavy snap rings if I didn't have the gears tightly secured in the vise with a pair these.

Good luck,
 

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Discussion Starter · #17 ·
HF bearing splitter worked a treat, the press was incredibly smooth, very little force needed.

Any tips on getting the key out? I'm never good at this sort of thing, ended up replacing them on my Porsche cams, but these look a bit more specialized.
 

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"cape" style cold chisel

Any tips on getting the key out? I'm never good at this sort of thing, ended up replacing them on my Porsche cams, but these look a bit more specialized.
I used a "cape" style cold chisel that had a narrow enough tongue to fit into the width of the keyway slot. Wear safety glasses. Place the tip of the chisel under the leading edge of the key and give it a couple of light taps with a hammer. The key should start to lift out. Here's the one I used:

http://www.tacomascrew.com/Products/Metal-Chisels/Proto-72-14-Cape-Chisels

You can't tell from their picture but the tip is only 1/4" wide.

Good luck. I know those keys can be stubborn. Resist the urge to clamp onto them and attempt to pull them out with vise-grips. That method only rips and cuts the chamfered edges of the keys and ruins them for re-use.
 
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