skotx

I'm trying to remove the rear main bearing with a modified puller and it just won't come out. I've already bent a set of aluminum arms and snapped two bolts. All washers and rings have been removed from above the bearing. The bending is kept under control by keeping the puller plumb to the shaft, but should I just move up to bigger bolts?

Anytime I'm exerting that much force on something I have to wonder if I'm doing it wrong. How much does it take to get that thing out? And how in the world do I get it back on when I'm putting it all back together?

Thanks,

Scott

tzbfwt

iTrader: (1)

I JUST went thru this. I bought the biggest two jaw gear puller I could findfrom Sears. Then go to home depot and buy two 3ft long pieces of 1/8 STEEL plate (one inch wide).

Make yourself 4 new puller links - each about 1 ft long - use these to replace the shorter plates on the puller. These links have to be steel - I tried using aluminum and I failed them - the bearing is on TIGHT. I had a friend crank on the puller while I kept it straignt with a pair of vise grips. We both had to stabilize the tranny with our legs (Tranny facing down on a concrete floor)You also want to use tie wraps or some other method to tie the puller arms together and keep them from slipping off the bottom of the gear.

Mahjik has a 5th gear syncro replacement posted somewhere with pics and DGeeseman? has an entire tranny rebuild also posted with pics.

In short - you gotta make your own puller, it takes two people and it is a Bit** to get that gear off. Mine is not back on yet, but the writeups say you pound it back on with a hammer - I'm going to use some 1 1/2 inch pipe as a driver and a block of wood to protect the bearing.

Jim

skotx

Thanks for the info Jim. I was just looking for some validation that it is in fact as hard to pull off as I'm experiencing.

Off to Home Depot...

dgeesaman

iTrader: (7)

Yeah, they aren't easy to pull. One guy said a pair of pry bars worked well, I used a modified puller like the others mentioned. The problem is the puller has to also remain cinched tight to the bearing or else it will strip over that metal band you're using to pull on. A pipe clamp with threaded rod seemed to help in my case much better than the tie-wraps.

My writeup is at www.davidgeesaman.com. Are you going for a full tranny rebuild?

Dave

Speed of light

iTrader: (8)

You may want to try using the puller with a slide hammer (rather than a straight puller). This is common for tranny work. If you are re-using a ball bearing, be sure to pull through the mounted race (not the free one--or risk bearing damage).

dgeesaman

iTrader: (7)

Is there any such slide hammer attachment that will work as a 2-jaw, long reach (15"+) puller? For the rear bearing it's the only way I see to remove it. You can't pull on the inner race of any of these (shafts stay in place until the bearings are pulled), and the only thing to pull on is the snap ring on the OD of the outer race.

Dave

tzbfwt

iTrader: (1)

Dave - I agree - there is no way to pull on the inner race of these bearings - and while a slide hammer of some sort might work, I think it will be

A. clumsy with the 15 inch long puller arms
B. Worse for the bearing

I'm actually doing two trannys at the moment - the first bearing was much tighter than the second, but the second still required two people - I'm not sure how you got yours off by yourself.

If you had to do your tranny rebuild over again, would you still do the whole thing or would you stop at the 5th gear syncro? It sounds like the shifter forks were not that worn - and your syncros were not that bad either? My tranny has 100K on it, and the 1rst to second shift could be a bit smoother (especially cold) - but I'm not sure I'm brave enough to go all the way thru it - it's just too easy to replace the 5th syncro and button it back up.

Jim

dgeesaman

iTrader: (7)

Would I rebuild it all again? Yes, but I'm not 100% sure. Of course, now I have the tools made so it's not a big deal. But it's a lot more mess. I really want to try the dual pry bar method since it seems quite effective and jdtotherescue claimed it worked really well for him.

For the 1st-2nd shift, there is an updated 2nd clutch hub assy and synchro (updated in mid-94). That should be a bit better than before, but will cost a couple hundred bucks. I would do all the synchros and bearings as a kit from gttransmissions.com and save some money. Also, if the bearings are going to be replaced, you can use pb blaster and stuff to make the old bearings come loose easier. But I used Mazda parts in mine - I guess I'd have to make myself comfortable that the gt trans parts are comparable to the Mazda ones.

Dave

tzbfwt

iTrader: (1)

OK - I was curious so I went to that site - saw lots of parts for GM Bubba Transmissions - but nothing for Mazda RX-7s - do you have to call them and special order a rebuild kit?

Let's see, Japanese manual tranny parts from some bubbas down in Georgia -why do I not have a good feeling about this?

Of course Mazda just raped me for a couple of 5th gear syncros and shift select spindles - and I AM a cheap Bastard....

Speed of light

iTrader: (8)

Originally posted by tzbfwt
I pulled my tranny at about 120K to replace a broken clutch fork. It seemed to be working so I decided to leave well enough alone and put it back in. A good tranny guy (who lived across the street from me) also suggested that I leave it alone--because he said it was a real PITA to overhaul and get it back together correctly.

Turns out this was poor advice--he was thinking in terms of putting around NOT performance driving. 10K later, at about 130K, I really started to regret not going through the tranny as the wear was becoming real evident, even in normal driving. The moral: trannys don't have infinite life spans; therefore, I would seriously consider refurbishing any high mileage tranny while you have it out. Keep in mind that tranny performance often degrades [with wear] very slowly and you don't really notice it until you drive a fresh, crisp unit.

I would also replace the engine's rear main seal and stator O ring while you have it apart (assuming it has high mileage on it too). I didn't and the rear main started leaking about 6 months thereafter. About $15 worth of parts from Malloy. Bummer!

Additionally, I would not use parts of unknown or untested origin because of potential materials compatibility issues. The potential for the metallurgy to be incompatible with mating components (and thus render poor performance and/or service life) is just too high. After years of experience, I have learned that there are often subtle, but important, differences in OEM vs. aftermarket parts. Aftermarket mfg's design their materials and components for a broad range of general use, not specific applications. And while they may work OK in some instances, there are many in which they are not as good as OEM.

Keep in mind that these HP trannys were designed for higher output / heavy duty usage without making them appreciably heavier. This was accomplished in part by using higher strength alloys, which are substantially stronger, but are also more expensive. It is not likely that rebuilder parts are going to have the same quality of materials even though they may look OK.

Finally, don't knock (no pun intended) the slide hammer until you try it. You can often thread a slide onto the end of a conventional puller, put the puller under light tension to hold everything together and then use the slide to break it loose. In this manner, I've been able to dissasemble things that otherwise defied removal. You are correct in that it could be harder on the bearing, depending on the type of bearing and the thrust it was designed to take. The most important thing, no matter what method you use, is to pull straight out and as evenly as possible [across the bearing]. Being cocked, even slightly, will substantially increase the pulling force nessessary for dissasembly. Using a slide hammer gives you an impact wrench type of effect which is often useful when things are assembled any tighter than a "light press fit."

dgeesaman

iTrader: (7)

Quote:

Originally Posted by tzbfwt

OK - I was curious so I went to that site - saw lots of parts for GM Bubba Transmissions - but nothing for Mazda RX-7s - do you have to call them and special order a rebuild kit?

This is what they said to me when I emailed:

"Dave,

We don't have them in stock, but can have the kit the following day. Prices are as follows:

Bearing Seal & Gasket set $178.95 (contains gaskets, seals and bearings)

Bearing Seal Gasket & Synchros set $374.65 (contains gaskets, seals, bearings & syncronizer rings)

If you need any further info let me know. For shipping quotes I would need a zip code.

skotx

*sigh*

I may have to concede and take this thing to a shop. I've now gone through two sets of aluminum arms and one set of steel arms. I can't keep the threaded part of the puller plumb to the shaft, so the arms just keep bending.

Dave,

Can you explain a bit about the pry bar method? It seems pretty simple but since it sounds like a two-man job, I'd think it'd be hard to put equal force on the bearing. And do you just bear down on the tranny housing? There isn't any room for something like a block of wood inbetween.

Thanks,

Scott

dgeesaman

iTrader: (7)

You didn't forget to remove a snap ring, did you? (ask me how I know, haha) They're a lot easier with those gone.

I haven't tried it myself since I learned about it after doing the job. The way I understand it, you've got the tranny end-up and you simply put a pry bar at each pull pocket, bear down on the aluminum housing and lift under the collar of the bearing. These are the kind of pry bars that look like large flathead screwdrivers that are bent about 1" from the tip. I think Harbor Freight has them for a decent price. Minor damage to the housing at the outside of the pocket is no big deal since it's not fitted to anything in particular.

Dave

tzbfwt

iTrader: (1)

Scott

what Zen-Master Dave said above: make sure all the snap rings are out ! Use his write-up and the one on Mahjik's site to be sure.

And have some one help you! It was a two man job for me. I also found a two jaw puller to be better than a three jaw puller - maybe it was just the better quality of the two jaw puller arms. Try some PB blaster between the bearing and the shaft - it should not be rusted - but it can't hurt

Jim

dgeesaman

iTrader: (7)

I laid the whole thing down on the floor and put the protruding driveshaft over a 2x10 (or two) so I could gently put my foot on the upper puller bracket. It seemed to keep things much more stable.



Do you have bolts/pins in the puller extensions to keep the puller hooks from swinging through the extensions?

Dave

skotx

I've read through both writeups... I'd be dead in the water without them. Above the bearing in question, I've removed the snap ring, the flat washer, the two half circles and their retaining ring. I don't think there's anything else to remove.

Dave,

I saw that pic in your writeup, but now that I look at a bigger version I might have realized my problem. The extension arms I've been creating are only 12" long, so the threaded rod of the puller starts at its lowest point, i.e., the point at which you could get the longest travel. If I made longer arms, I could start about halfway up and I bet the threaded rod wouldn't want to tilt as much. I'll also try laying it on its side as you suggested.

Regarding your bolt/pin question, I just have four bolts and nuts connecting the extension arms to the original 6" puller. You mentioned a "pull pocket." I hadn't noticed anything like that... is that an indentation on the underside of the bearing? Perhaps I should have done more research.

All this for a 5th gear synchro! Thanks for the help guys.

dgeesaman

iTrader: (7)

I'm sure you're fine, but there was a point (front inputshaft bearing IIRC) where I was pulling on it and forgot the remove the snap ring. Talk about aggravation over nothing.

That's my mistake - the other tranny bearings are seated tightly in the gearbox housing and lay flush - and I was thinking of that situation. There are two pockets which give you access to the OD of the bearing to pull it. This is where the pry bars are an option.

I'll bet you need some PB blaster on that inner race, or to try using a slide hammer of some sort. Once you get it started it's no problem - it seems yours is slightly bound or stuck. If you're not using the bearing again (they're only like $25), you could heat it up really well with a propane torch.

Dave