after market diferential parts

[fred79]

I am rebuilding prepping still to rebuild a tranny to replace the one that grenaded.
does any one sell after market parts to rebuild the differential and replace the pins to prevent the differential from grenading again.
also any one know which helms manual i would need to do this.
thanks
fred

 

[Machspeed]

I didnt know you could rebuild a grenaded diff.

 

[AutoSHO]

FOR SHO:
I didnt know you could rebuild a grenaded diff.

He's rebuilding a transmission to replace his blown one.

 

[fred79]

correct I am rebuilding a used transmission and don't want to repeat this any time soon

 

[Machspeed]

Oh lol. I see 2 options to prevent a grenading diff, 1)dont burnout, 2)Quaife

 

[projectSHO89]

FOR SHO:
Oh lol. I see 2 options to prevent a grenading diff, 1)dont burnout, 2)Quaife

Bingo! Those are your two choices.

Get SHONut's tranny video and a copy of any of the Helms that includes the MTX-IV. (89 is a special small manual for the SHO specific stuff, 90-95 is all-in-one).

Steve

 

[yamahaSHO]

Psshhh... Go for the Quaife wink

 

[masho95]

The only two sure ways to keep if from grenading again are already listed above. I'm not sure if the differential pinion kit is available aftermarket, but I'd say probably 90% not. Someone listed a transmission rebuild kit available before from www.driveline.com or something like that before and I'm not sure what tranny parts they had available. The Ford kit is of course now obsolete, and as of the end of last year I think only 1 or 2 kits were available and promptly purchased. You might want to just pull out the pinions and pins and check their condition. Depending on the mileage of the tranny you got they could be ok, depends on the drivers style of driving I've pulled out the pinions and pins on a 120K mi tranny and they were almost mint compared to my tranny which had like 85K-90K mi. on it and the pinions had massive grooves in them. Anyways check what you have first and then start looking.

 

[Bizzy]

There are a few other things that can be done as well to prevent a stock diff from grenading....though the no burnouts and quaife are the extremes in cheap to expensive preventatives.

Just FYI, a friend of mine who doesn't do burnouts and never has had his diff blow. So it is possible for a diff to blow even though no burnouts or abuse has taken place.

<small>[ December 11, 2003, 07:56 AM: Message edited by: Bizzy ]</small>

 

[gmorrell]

I don't have to worry about this because I have a Quaife diff, but why doesn't one of you bright entrepreneurial types come up with a simple fix to prevent the OEM diff from ejecting the pinion gear stub shafts?

How about a simple steel collar that presses over the outside of the diff case and covers the ends of the pinion gear shafts? A sort of differential prophylactic if you will...

****, you might get lucky and find a diameter of off-the-shelf thin wall steel tubing that could simply be cut into rings.

 

[TYSHO]

Gary M.:
I don't have to worry about this because I have a Quaife diff, but why doesn't one of you bright entrepreneurial types come up with a simple fix to prevent the OEM diff from ejecting the pinion gear stub shafts?

How about a simple steel collar that presses over the outside of the diff case and covers the ends of the pinion gear shafts? A sort of differential prophylactic if you will...

****, you might get lucky and find a diameter of off-the-shelf thin wall steel tubing that could simply be cut into rings.

I am in the process of that at the time as we speak! Once I crack the case, the mystery will be told....did the old pin with out weld bust or the new pin with the welded shaft bust?

I drove it hard and did burnouts like crazy and managed to blow the diff pin in ONE day after assembly...105mph in 3rd w/WOT....SHO BOOM...4th gear WOT 120mph...Smoke at least an 1/8 mile back like a flying jet. Yeah, I'm crazy!

It's a 50/50 chance as to what pin gave as the differential in there was a previous blown one with a new shaft. The casing around the differential was fine accept for the circular opening of where the shaft seats. It was wider, oblong, as the shaft had no where to go and just grinded like crazy against the rivets on the diff. So, this might be a risk too as the new shaft went back in and the rest of the opening was filled with welding.

Time will tell, but time can be with held as it's pretty chilly this time of year to be doing tranny work!

Edit: It would'nt hurt to edit the subject line for future member searches! Spelled correctly; Differential. thumb

<small>[ December 12, 2003, 05:58 AM: Message edited by: TYSHO ]</small>

 

[shobikes]

I'd like to hear about some of the options in between no burnouts and Quaife. In my dreamy future, I have the time and $$$ to install a Quaife, but in my daily driver I dodged a bullet last night. Intending to simply bark the tires, I laid the coolest 50yd-long burnout I've ever done, and on dry pavement. I mean - I've heard stories, but this was pretty intense, and I found I simply couldn't lift after the thing was started... shrug

So Bizzy - what are some of those options? I've seen photos of the inside of one of these things, and it seems there are two major weaknesses - the pin itself, and the alloy casting it presses into. The pins seem to either break outright, or to work themselves out over time, elongating the holes in the diff housing. So is there a hardened pin that won't break (or is less likely)? Then - is there a way to ensure it doesn't walk out? The metal ring sounds good, or perhaps a spring-type roll pin thru the pin and housing, just as insurance?

I really like the idea of a collar of some sort, so that if the pin does shear or crack, it stays in place, doing little harm. Has anyone addressed this as deeply? It can't be impossible. I tell ya what - I have a seized up parts tranny. I'll get back to you...

 

[Shoaz]

shobikes:
I'd like to hear about some of the options in between no burnouts and Quaife.

Spool? Just weld everything together and put it back in. wink

burnout

 

[drivinhard]

ROTFL. Great comparison! Putting a "collar" on it is like using a prophylactic with STD's, it may keep everything in, but it sure as heck ain't even close to fixing the problem!

I've seen 2 problems, the locating roll pins that hold the pinion shafts can sheer. This allows the pinion shafts to start to walk out of the diff, eventually they walk out far enough to grab the case, and bam. The other thing, is the spider gears can actually gall down on the pinion shaft themselves, and wear down the pinion shaft, and you can have a pinion shaft actually break, even while still in the diff housing. So yeah the band may keep all the guts in, but meanwhile the diff is eating itself to pieces, throwing debris all over the rest of the tranny.

There is no cheap fix, the quaife is the really the only game in town. If I ever bought another stock SHO, that would probably be the first thing I'd do (after changing the oil).

You can use good synth fluid to help prevent galling on the pinion shafts, and maybe somebody can come up with some stronger roll pins. Still band aids though, doesn't do anything to cure the design.

 

[TYSHO]

This is getting a little confusing. How the **** can the friction wear down the shaft to cause breakage? The spider gear doesn't spin around the shaft until the spider gears come into play, IE: One wheel burnouts or wheelspin. So under normal driving conditions or WOT straight line conditions, the gear will not spin around the shaft for any friction to happen. Did you do a donut for 24 hours in a little circle w/out fluid or what? That's weird, not saying it's impossible, just crazy! Maybe the reason was of a dry trans, no fluid, in where extreme tempatures can be seen. But still, it can't happen like that, but over time with cheap low fluid or ****.......this crap is scattering my brain. Damn! Just keep some fluid in there! Sheeez, time to catch some sleep and let my mind rest.

Edit: Mark, I hope your not feeding this story out to make more people buy the Quaife. That's like an extreme one in a billion kind of case, if possible. Or just an old myth possibly? If it does happen, we would've seen this as a case like the diff pins. Sorry, but that just sounds a little to insane. That's like saying the excessive friction from the trans bearings caused the bearing cups to crack or split open. Again, extreme!

Sorry if this came off in the wrong way, but it's not intended to. thumb beer

<small>[ December 13, 2003, 03:46 AM: Message edited by: TYSHO ]</small>

 

[drivinhard]

Why would I "feed" a story out to make people buy more quaife's?

"The spider gear doesn't spin around the shaft until the spider gears come into play, IE: One wheel burnouts or wheelspin"

Exactly. When you beat on it, the spider gears can gall the pinions shafts. Under normal driving, that doesn't/shouldn't happen. Old/low fluid doesn't help the issue either.

My 92 has 185k and never had diff problems, and has been on the track and at the strip lots of times. The stock diff isn't going to fail that often under normal usage, and can tolerate some abuse, but only for so long.

Frankly I see the Quaife as a (or the) best performance improvement you can bolt on a SHO. The durability is just icing on the cake. Ask anybody who's put one in if they are worth the $$. I don't think you'll find anybody that will say it wasn't worth it, or that they would go back to an open peg leg diff. The performance difference is night and day, and it's nice to not have to worry about it coming apart on you.

 

[gmorrell]

TYSHO:
This is getting a little confusing. How the **** can the friction wear down the shaft to cause breakage? The spider gear doesn't spin around the shaft until the spider gears come into play, IE: One wheel burnouts or wheelspin. So under normal driving conditions or WOT straight line conditions, the gear will not spin around the shaft for any friction to happen.

Actually, the only time the spider gears aren't spinning on their shafts is when the driven wheels are turning at exactly the same speed. The spider gears turn whenever there is even the smallest difference in halfshaft speed. That's how open differentials work.

During a one-legged burnout, the driven wheel is turning at twice the input RPM to the differential, and this situation creates some rather extraordinary forces on the diff internals.

Auto How Stuff Works: The Open Differential

 

[revhardSHO]

would it be possible to drill a larger diameter bore for stronger pins?

 

[TYSHO]

Okay, this is what I was trying to get at, exactly. With good fluid in the trans and the correct level, it would be rare to happen.

Gary, I understand how it works, but under the condition you spoke of, the friction is nothing to worry about as it's minor and the gear will be bearly spinning if any.

Now I have another question! Being you have six gears in the diff, how would the spider gears have enough slack to put excessive pressure on the shaft in order to break it? So you have your side gears (in where the axles lock in), pinion gears (inbetween the side gears located on the top and bottom), and then you spider gears (inbetween the side gears located on the sides, in which the pinion gears are on top and bottom). Now that is said, it's in a box shaped and being retained, how could it move around? shrug

About the roll pins, they're pretty damn strong and I'd stick with them before putting something solid in it's place. If you change them out every clutch job, there's nothing to worry about...hopefully! Burnouts are not the only thing to cause them to break. Over time, very hard braking can cause them to give...especially high speed hard braking. Roll on downshifting is just as bad! So if you think not spinning the wheels, but downshifting to 3rd at 85mph or 2nd at 50mph is okay...wrong, it's just as much as launching with some wheelspin.

beer

<small>[ December 13, 2003, 08:42 PM: Message edited by: TYSHO ]</small>

 

[drivinhard]

I've seen the pinion shafts where it looked like somebody put it on a lathe and turned it down .040" where the spider gear rides. One of the worst I ever saw was from Sergio P's car, showed it to me at the '99 Convention. he's in TX, swing by his shop sometime, he's probably got it sitting in his toolbox

Personally, I would not consider the roll pins "strong". I wouldn't consider them "weak" either, but more borderline adequate.

A full fluid level (w/ fresh fluid) can protect against pinion shaft galling, but does nothing for the load against the roll pin. And correct, it's much more common for the roll pin to sheer, than it is for the pinion shaft to break (more rare like you said) but I've seen it happen a few times.