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Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 1:24 am
by SuperSLE
Just bookmarking this thread for me

Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 11:08 am
by willwren
I pick up the rest of the parts today after work. I actually didn't work on it last night, as there wasn't much I could do without what I don't have (want to replace). I still have to swap WP pulleys too, but I'll probably do that tonight. I'll also be cracking the pan loose for a 30% fluid change and filter. This filter has been in since the rebuild anyway, and I've got some aluminum shavings (microscopic) very likely trapped in there from the inside of the tailshaft housing.
I have my indicator setup to check the endplay with, and I'll take some good pics of that when I have it set up. Then I'll know what thrust washer to order (all are available from the dealer at least overnight), and they have all the sizes in .010" increments. I COULD laser machine my own shims, but I'd feel better with a single thrust washer of the correct thickness. Target is .005"-.025" of endplay.
I also had a good 5-minute conversation with regards to pinions, roll pins, and LSD's with Todd Allen yesterday (he'd called me about something else, and I took advantage of his ear while I had him at my mercy). I feel alot better about the odds of this LSD surviving in a car that likes to eat OEM or beefed up Diff's.
Anyway, I'll take more detailed pics during reassembly, as it looks like at least the Doc is interested in a bit more detail.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 11:12 am
by SuperSLE
willwren wrote:
Anyway, I'll take more detailed pics during reassembly, as it looks like at least the Doc is interested in a bit more detail.
Yes please. Trannies are a new learning adventure for me that I will likely be diving into this year at some point. So this is awesome.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 4:20 pm
by Boss455
Same here, I feel I won't make it to 200k on this tranny. I don't think the last owner was very nice on her. I wanna know what I'm in for when I get her rebuilt!
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 4:25 pm
by willwren
Keep in mind I'm not doing anything closely resembling a rebuild here. I've simply removed half a dozen parts out the tailshaft housing. This trans was performance rebuilt to the limits in November of 2005. I'm simply swapping to a modified output shaft and LSD.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 4:33 pm
by petraman
So is this a rebuilt differential with the LS added to it, or is it a whole new piece?
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 4:35 pm
by willwren
This is a good 3.33 (stock) differential that was converted to LSD by EP. Replacing a beefed up OEM 3.33 differential that had unknowingly started to fail, which replaced the stock from the factory 3.33 diff that snapped in 2005.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 7:59 pm
by dirtracr95
willwren wrote:Keep in mind I'm not doing anything closely resembling a rebuild here. I've simply removed half a dozen parts out the tailshaft housing. This trans was performance rebuilt to the limits in November of 2005. I'm simply swapping to a modified output shaft and LSD.
what was done differently that makes it a performance rebuild? And whats these limits Ive never heard of limits
what was beefed up besides the pinion shaft in the Diff that just failed?
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 9:04 pm
by willwren
Dirtracer95, I'm not going to go into a long dissertation on my trans build in this topic. If you want to know, go search on the old forum. It was built for me by a guy renowned in the valley here for performance builds, and cost me dearly. Dozens of members here have seen the list in the past, and can assure you just as well as I can, that it was built VERY well and gauranteed to hold. What my builder didn't count on was an intercooler and another drop in pulley diameter.
I was involved in the entire rebuild from day 1 until I took delivery. He has since also rebuilt the SLEeper's trans for me as well, but not to the same level. If you want to talk to my builder about my trans, I'll give you his number, and tell him you're going to be calling. That good enough for you?
Last time I checked, this topic was about an LSD install, not about something that happened back in 2005.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 9:18 pm
by dirtracr95
ok so your LSD is going in a stock diff? Did you consider rebuilding the beefed up diff and having the LSD installed in that?
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 9:29 pm
by willwren
No, I didn't consider having the LSD made from the beefed up diff, as it was in my car at the time. I sent a core like all of EP's customers do. The purpose of an LSD solves all the problems I've had with the stock diff and the beefed up diff. The pinion and roll pin are far less of an issue with an LSD. EP LSD's have held up to far more power than I'm putting down, with and without drag slicks. We've had one running at WCBF for 3 consecutive years.
If you're still hung up on my rebuild, you can find most of the parts that were replaced/upgraded on my webpage. You'll have to search through thousands of pics, but it's not too hard to find. Our entire Gearhead team 'participated' in my rebuild as it progressed.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 10:22 pm
by sandrock
I will say that this diff Bill has now originally came from my '93. When I disassembled the trans (it had been slipping very badly, so I replaced it with a '95 Riv-based unit), I found that diff to be nearly new. This led me to believe that the original diff exploded sometime in its past, and a new diff was installed. Bill found out I had it stuffed away in my attic and held me at virtual gunpoint until I gave it up.
For all intents and purposes, consider this diff new as I doubt anyone will find a nicer unit anywhere unless its NOS. Couple that with the mods that have been done to it, and it should hold up for a while.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 10:23 pm
by SuperSLE
Now I know Intenses opinion on the LSDs and I have read EP's stuff. But what about ZZP's claim that stock is better than an LSD?
The other differentials on the market are clutch based. They are factory differentials with the internal gears cut down and tiny clutches placed behind those shaved gears. The gears are weaker than stock and the clutches are not strong enough to transfer any power from a spinning wheel to the other side. The clutch type differential will not aid in launching, nor last as long as a stock differential.
Just trying to learn here a little.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 10:47 pm
by willwren
Believe me, I researched. There are other options for the 4T60, and those options have horrible track records. The EP shines through every time. I've searched all related forums and have never found a proven case of an EP failure, other than in EXTREME cases. I've talked with PontiacJeff several times, and exchanged dozens of emails. I've never had any reason to doubt his claims from any evidence I've searched for. Silverbullet has run his EP 3 or 4 consecutive WCBF's on drag radials as well. I have to give credit to Jeff though, in spite of the time and difficulties I experienced, as he was going through some life-changing events during the last year.
I'M BEING AS FAIR AND UNBIASED IN THIS POST AS I HAVE TO BE AS AN ADMIN OF THIS FORUM. Keep that in mind as you read. My advice, should you be interested in an EP LSD would be to check on the turnaround time. I don't know if my case was unique or not, or if things have changed since mine was ordered.
From all the LSD research I've done, I'd have to say the INTENSE Gen3 LSD and the EP are everything they claim to be. The only issue is with regards to timeliness.....or customer service, but not to a serious extent. Jeff made me a gesture, as I was cheated out of an EP diff by a former Vendor we had (who ran of with thousands from several members). It took some time to get that LSD to me after Jeff realized I was the one that was cheated years ago.
From a reliability standpoint, however, I'd rank the EP and INTENSE both very high. The Gen3 data on other forums has to be carefully filtered to remove the INTENSE-haters out there though. It's tough. They cloud the true picture.
The EP is expected to last 80k befor the clutches need replacement with 'normal' use. They no longer offer a 'street' tuned diff, only 'track'. From my research, I feel that was a wise decision on Jeff's part.
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 11:12 pm
by SuperSLE
Very interesting, now what was the cost for that diff, keeping in mind that it is for a different tranny than most of us are using, but I would bet they are pretty similar in cost?
Re: Double busted club for the Zilla.
Posted: Wed Mar 04, 2009 11:32 pm
by willwren
For price, the best I can tell you is to contact EP and ask (engineered performance).
Back on to the work, I made SOME progress tonight, but was frankly BEAT from work before I even got started. Here's a few pics (my apologies in advance, I got the obligatory beer pic in, but the dog was inside napping, and I didn't want him near the dripping trans pan):
A few of the parts ready to go in/back in:
Diff end of the old and new output shafts. See how I had to machine the groove deeper on the new one to work with the diff:
The 'hole':
Friction disc and thrust washer between the tailshaft housing and diff. This is what 'sets' the driveline end play. After install, I'll check again, and this thrust washer will likely change in thickness:
Invaluable tool. The slide hammer made it very easy to remove the output shaft:
Notice the jaws I used are curved to 'hug' inside the retaining ring groove on the shaft:
Another useful bit of hardware should I have to remove the LSD before final assembly (it'll be held a bit differently than a stock diff):
The broken rollpin in Diff #2 (eaten by the Zilla, just like Diff #1):
Now look carefully at this pic for the odd patterns:
and look at this one for why:
None of the particles trapped by those hard drive magnets ever made it to the filter. These magnets are far stronger than the OEM pan magnet. Now imagine they were circulating. That means wear. But not on either of my rebuilt transmissions. Nor either oil pan. Even if it means 5k more miles on either of them, it was worth this free mod.
(have patience with me on this job.......I'm only working on it in the evenings after work, as my weekends are primarily dedicated to Katie, and I've been working crazy long hours)
Re: Double busted club for the Zilla.
Posted: Sun Mar 08, 2009 9:04 am
by mhfromphila
Bill, I fix lift trucks and when roll pins brake we use sprial roll pins in there place.

Re: Double busted club for the Zilla.
Posted: Sun Mar 08, 2009 11:09 am
by willwren
The strength of that pin isn't a concern with the LSD.
Re: Double busted club for the Zilla.
Posted: Sun Mar 08, 2009 9:11 pm
by willwren
UPDATE:
After the output shaft is removed, the weight of the driver's side axle will drop the reaction drum on that side to an odd angle. Gravity sucks. This prevents insertion of the output shaft, as you can't get the splines on the 'deep' end to mate with the reaction drum. I had a friend stop by, and used him to hold my right side axle up and 'wobble' it around until the splines meshed, then apply some force towards the passenger side on the axle to oppose me whacking the output shaft into the reaction drum to get the clip to catch and drive through. I used a 2x4 and a big rubber mallet to do this, as I don't have the GM tool, which is too large to do this 'on car'.
I'm heading back out now to check endplay in the final drive. This will be done with the LSD and 'intended' housing, as both induce variables into the final amount of play. I'll take pics of the setup (the best I can, it's tight in there) shortly. If the endplay is more than .005-.025", I'll have to order a new thrust washer (they come in .010" increments) which will delay FINAL assembly until tues/wed.
Re: Double busted club for the Zilla.
Posted: Sun Mar 08, 2009 11:14 pm
by willwren
Ok, here's the most recent batch of pics. Where the car sits right now is the tailshaft housing is installed, with the output shaft and LSD behind it. Final end play was supposed to be .005-.025", and ended up coming in at .0105". No need to order and install another thrust washer for the Diff side.
After the output shaft was installed (detailed above) and the LSD and tailshaft housing temporarily installed (no lock rings yet):
I inserted a round piece of brass for the dial indicator to sit read off:
Set up the dial indicator to read off the brass that was resting against the LSD, then pried the LSD back and forth using a screwdriver in the VSS hole to get the endplay measurement:
With a .0105" measurement, everything was great. Took off the tailshaft housing to be able to remove the brass, then installed the retainer clip. This isn't the OEM flat ring for the LSD, but rather the square-cross-section axle clip that I modified the tailshaft housing to accept. Here's the clip ready for the LSD to be 'snapped over':
Now the LSD:
Here's the thrust washer and friction washer as the LSD would see them:
The new seal in the 'new' tailshaft housing (pressed at work on Thursday):
VSS? Time to move it over from the old housing:
But first I have to clean off the steel shavings from the trans wear and LSD failure:
LSD ready to be covered up:
And tailshaft housing torqued to 22-30 ft lbs:
The price I paid today:
The trans filter and pan are already installed and torqued. I have to install the engine mount bracket, dogbone bracket and mount, as well as the passenger side axle, hub, brake rotor, and caliper tomorrow, then both front wheels. At that point, I'll top it off and run the car on jackstands to test function. Should have the Zilla rolling out no later than Tuesday evening after work.
I cannot overstate the importance of a digital camera and a good set of FSM's to get things right. But I should warn you that the FSM does not detail this process outside the normal rebuild process. The output shaft removal is not detailed in the FSM with the trans installed.