28 Spline Stub Shafts?

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28 Spline Stub Shafts?

Post by PDenbigh » Thu Apr 14, 2011 11:35 am

What's happening Merkursport!

I'm putting a 7.5" Torsen T2R diff in my track car, but in order to do so I need 28 spline stub shafts (that go in the diff) instead of the stock 26. I post this for two reasons:

1. Has anyone addressed this already?
2. If not, I'm going to have custom stub shafts made. Anyone else interested? Probably be a one-time thing.

Thanks!
Peter
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Post by DPDISXR4Ti » Thu Apr 14, 2011 12:26 pm

Peter- How the hell are you?

Rather than custom stub-shafts, have you considered getting the GM-spec Torsen, which will be 26-spline? Just make sure you get the right pitch on the splines since there may be a couple different ones used.
Brad

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Post by PDenbigh » Sat Apr 16, 2011 10:30 am

DPDISXR4Ti wrote:Peter- How the hell are you?

Rather than custom stub-shafts, have you considered getting the GM-spec Torsen, which will be 26-spline? Just make sure you get the right pitch on the splines since there may be a couple different ones used.
Hey Brad! Doing well - busy but good. You?

The T2R only comes in 28 spine GM-spec, thus my dilemma. So, that's what's on its way here - a 28 spline 7.5" GM diff. The T2R is the only helical diff with enough preload that it's well suited for road racing too, so I'm stuck.

I've seen a few folks that have mated the end of a 28 spline F-body axle to IRS flanges, so that's likely the route I will take. If I can't get that to work, I'll have to get custom ones made (yuk).
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Post by John V » Sat Apr 16, 2011 10:48 pm

PDenbigh wrote:
DPDISXR4Ti wrote:Peter- How the hell are you?

Rather than custom stub-shafts, have you considered getting the GM-spec Torsen, which will be 26-spline? Just make sure you get the right pitch on the splines since there may be a couple different ones used.
Hey Brad! Doing well - busy but good. You?

The T2R only comes in 28 spine GM-spec, thus my dilemma. So, that's what's on its way here - a 28 spline 7.5" GM diff. The T2R is the only helical diff with enough preload that it's well suited for road racing too, so I'm stuck.

I've seen a few folks that have mated the end of a 28 spline F-body axle to IRS flanges, so that's likely the route I will take. If I can't get that to work, I'll have to get custom ones made (yuk).
I wonder why you chose to do things the most difficult, and yet, not very strong way possible?

I hear there's stronger design diffs with a choice of spool, locker, twirly gear-one wheel peel wonders and (gasp) 3 or 4 pinion clutch plate LSD---what serious cars generally choose first.

I've heard some guy just picked up another for $30..

With bigger half shafts--30 spline
That's bigger than a lot of those Ford 8.8" things with their weak 2 pinion designs...

I don't understand...
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Post by PDenbigh » Sat Apr 16, 2011 11:12 pm

John V wrote: I wonder why you chose to do things the most difficult, and yet, not very strong way possible?

I hear there's stronger design diffs with a choice of spool, locker, twirly gear-one wheel peel wonders and (gasp) 3 or 4 pinion clutch plate LSD---what serious cars generally choose first.

I've heard some guy just picked up another for $30..

With bigger half shafts--30 spline
That's bigger than a lot of those Ford 8.8" things with their weak 2 pinion designs...

I don't understand...
Hi John.

I appreciate your suggestion for the Supra diff (if that's what you are suggesting?).

Unfortunately, Torsen doesn't make the T2R for the Supra. It's the maintenance-free design (no clutches), the consistent performance (no clutches), the preload, and the fantastic reviews from fellow road racers that has me so interested in it. Plus, by using the stock diff, I only need to modify the stub shafts. No new mounts, no driveshaft adapters, half shaft adapters, etc. Though the lack of gearing is unfortunate, I'm just not fast enough (or have enough time) that a gear change per track is needed.

If my car breaks the GM 28 spline axles, I'd be thrilled :) . Realistically, though, I won't be putting down any more HP than a slightly tweaked LS1 with much lower shock load, so I think they'll be fine.

There are more difficult ways to make this happen. Changing two stub shafts isn't so bad. Especially if I send the drawing to a driveline shop and two weeks later they arrive UPS.

If it doesn't work out I'm happy to talk to you about what you can offer.

For reference, what sort of investment would I be looking at for a turn-key helical limited slip, plug-and-play Supra setup for an XR?

Thanks,
Peter
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Post by John V » Sun Apr 17, 2011 12:02 am

PDenbigh wrote:
John V wrote: I wonder why you chose to do things the most difficult, and yet, not very strong way possible?

I hear there's stronger design diffs with a choice of spool, locker, twirly gear-one wheel peel wonders and (gasp) 3 or 4 pinion clutch plate LSD---what serious cars generally choose first.

I've heard some guy just picked up another for $30..

With bigger half shafts--30 spline
That's bigger than a lot of those Ford 8.8" things with their weak 2 pinion designs...

I don't understand...
Hi John.

I appreciate your suggestion for the Supra diff (if that's what you are suggesting?).

Unfortunately, Torsen doesn't make the T2R for the Supra. It's the maintenance-free design (no clutches), the consistent performance (no clutches), the preload, and the fantastic reviews from fellow road racers that has me so interested in it. Plus, by using the stock diff, I only need to modify the stub shafts. No new mounts, no driveshaft adapters, half shaft adapters, etc. Though the lack of gearing is unfortunate, I'm just not fast enough (or have enough time) that a gear change per track is needed.

If my car breaks the GM 28 spline axles, I'd be thrilled :) . Realistically, though, I won't be putting down any more HP than a slightly tweaked LS1 with much lower shock load, so I think they'll be fine.

There are more difficult ways to make this happen. Changing two stub shafts isn't so bad. Especially if I send the drawing to a driveline shop and two weeks later they arrive UPS.

If it doesn't work out I'm happy to talk to you about what you can offer.

For reference, what sort of investment would I be looking at for a turn-key helical limited slip, plug-and-play Supra setup for an XR?

Thanks,
Peter
The clutchs in good designs, those that lock somewhat more than the weak 35 ft/lb wonders sold for 'merikan stuff last literally for years and years and years.
It depend on how much they are forced to differentiate---logically enough..
Set tight---and we are trying to maximize grip, they won't be differentiating all that often, ipso facto they don't wear appreciably.
One 5 year period in my Saab I must've done 20,000 mile on gravel and asphalt and the break away torque had only dropped maybe 4-5 ft/lbs to around 90 from the 96-87 ft/lbs I set it.

I just feel the endless 930 years I have heard it) clutch plates wear! song is never accompanied by "because I have worn lots of them out"..

You think there is not going to be wear in the Torsen?

None of the twirly gear things ever want to talk about the wear... How do you think the twirly thrust is resolved???
It ain't pretty.

Better reshim a clutch plate diff every 25k miles of hard use than $#!*-can a whole diff.

Can't say what a Supra diff and a twirly gear diff might cost---it all depends on the price you get the Supra diff for. I just got another for $32.95
4.3 this one.
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Post by DPDISXR4Ti » Sun Apr 17, 2011 10:09 am

PDenbigh wrote:The T2R only comes in 28 spine GM-spec, thus my dilemma. So, that's what's on its way here - a 28 spline 7.5" GM diff.
I'm pretty certain that you'll be breaking new ground with this one Peter - hopefully it doesn't require too much grinding on the case - I've seen some of the GM-spec differentials that didn't require any. There's also the ring-gear spacing to sort out - seems some require spacers and some don't.

Welded hybrid stubs would be new ground too. Bubba's Welding and Lawn Mower Repair need not apply. :lol:
Brad

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Post by Duecento » Sun Apr 17, 2011 11:23 am

Welding axles is always a bad idea. In this case it is a monumentally bad idea. As long as you are just doing a burn out you probably are not in danger of losing your life when the axle and flange part company. At 100 mph, that might be another matter.

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Post by Duecento » Sun Apr 17, 2011 11:28 am

Have you contacted Torson to see if they would build you one with the spline you want? That would be a much better way to go.

I just looked at the Torson site and was surprised to see that the new Torson stuff is not the same design as the original which worked on the principle that a worm gear train can be driven from one end but not the other, so one axle could overrun the other, but neither could rotate more slowly than the case. Instant, smooth torque biasing without clutches, so there was nothing to ever wear out.

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Post by John V » Sun Apr 17, 2011 11:50 am

Duecento wrote:Have you contacted Torson to see if they would build you one with the spline you want? That would be a much better way to go.

I just looked at the Torson site and was surprised to see that the new Torson stuff is not the same design as the original which worked on the principle that a worm gear train can be driven from one end but not the other, so one axle could overrun the other, but neither could rotate more slowly than the case. Instant, smooth torque biasing without clutches, so there was nothing to ever wear out.
Where is the side thrust on all those little worm wheels resolved?

You are reading ad copy. I am asking something after talking to people in 4 countries who have been disappointed with the wearing out of the twirly gear diffs lifespan, after suffered several years of one wheel peel in vigorous driving---when the inside wheel unloaded, the diff would transfer a percentage (depending on the helix angle) to the outside wheel and a % of ZERO is.... in the end the tire would spin...

Reality sometimes conflicts with ad copy.
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Post by Duecento » Tue Apr 19, 2011 6:59 pm

In the real worm gear differential it is not much of an issue. Certainly not nearing the loads on the rest of the differential. Remember that one axle can overrun the other so only the less loaded of the two axles is rotating versus the carrier. They are in essence a gear drive Detroit Locker.

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Post by John V » Wed Apr 20, 2011 1:39 am

Duecento wrote:In the real worm gear differential it is not much of an issue. Certainly not nearing the loads on the rest of the differential. Remember that one axle can overrun the other so only the less loaded of the two axles is rotating versus the carrier. They are in essence a gear drive Detroit Locker.
Locker?
Even in vigorous driving with just dynamic unweighting of the inside tire those thing go effectively open.

And the helical angle generates crazy amounts of thrust which is resolved into the ends of the gears against the case: big friction, big heat on a small gear.
It was a smart design when the patent was issued......................in 1916.

But with the serious drawbacks, unpredictable loss of drive like an open diff, and associated tom-foolery and cost, I cannot see the advantage in the choice.
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Post by Duecento » Wed Apr 20, 2011 3:07 am

If you have a spool and lift one tire off of the ground and "it is effectively open" as you say, but so what? There are no magic beans that do any better than that. Its all limited by the traction of the tires in the end.

As for the end thrust, it is not very large compared to the other forces acting on the final drive. Remember that the action of the worm gears is on the less loaded axle. Also remember that the axle with the greatest traction is the one that is turning the slowest and the worm gears ARE NOT moving on that side of things, only on the overrunning side.

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Post by John V » Wed Apr 20, 2011 9:55 am

Duecento wrote:If you have a spool and lift one tire off of the ground and "it is effectively open" as you say, but so what? There are no magic beans that do any better than that. Its all limited by the traction of the tires in the end.

As for the end thrust, it is not very large compared to the other forces acting on the final drive. Remember that the action of the worm gears is on the less loaded axle. Also remember that the axle with the greatest traction is the one that is turning the slowest and the worm gears ARE NOT moving on that side of things, only on the overrunning side.
Spool!?
You seem to like to change terms.
If I have a spool I have some thing that has a flange for a ring gear, two registers for bearings and splines for the two driveshafts: 1 solid piece, no open ever.

Image

Sorry but I am beginning to suspect that you are speaking from a purely "non-applied actual experience" point of view, so rather than continue this really confusing thing---it is not discussion, nor is it debate, I will ask straight out:
Have you yourself ever worked :
Multi-disc clutch plate diff
VC LSDs either stock or modded
Twirly gear
Spool
Locker (Detroit or whatever)??????

????
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Post by Duecento » Wed Apr 20, 2011 11:56 am

Spool!?
You seem to like to change terms.
If I have a spool I have some thing that has a flange for a ring gear, two registers for bearings and splines for the two driveshafts: 1 solid piece, no open ever
Yes, I know what a spool is. What did you mean by saying inside tire traction made the differential "effectively open"? I was trying to say that the worm gear differential is no more open than a spool except when one axle overruns the other and that any loss of traction by one tire does not change that. What were you trying to say?


nor is it debate, I will ask straight out:
Have you yourself ever worked :
Multi-disc clutch plate diff
Yes
VC LSDs either stock or modded
Once
Twirly gear
Nope
Spool
Yes
Locker (Detroit or whatever)??????
Detroit - Yes, Whatever Locker - Yes, I have a LocRite/8" w/3.55 gears out in the Conex box that may go into a Pinto for drag racing.

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