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Installing Quaife LSD

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darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Hi Richard,

Thanks for the info. I've been preparing a check list of the all the things to measure, at which times in the disassembly, because I know that once I dive in I might end up with it all apart and nothing measured or documented!

Interesting about the GM 7.5. I'm planning on reusing my spacer, as I understand you only have to get it around 0.010" longer. I wonder if the GM 7.5" collapsible spacer would be an option as well?

Is this the spacer kit you are referring to?

https://www.summitracing.com/parts/rat-4111/overview/



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

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diver Richard Crothers
NorthEast, Maryland, USA   USA
Yes Darrell,

That spacer kit is what I was mentioning. Hint, do not put rear seal in until you have what you need for shims.

Richard

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Hi Richard,

Thanks, I went ahead and ordered that kit, too, in case I want to go that way.

A question for anyone that had done this, in reading some about rear end rebuilds, I'm seeing things like 200-300 ft-lbs needed to compress the spacer. Does ours take that much? If so, how do you keep the pinion from turning? Most of the rear ends I've found information for just have a single nut that both sets the preload and secures the flange/yoke. But ours has two separate nuts, can you get to the pinion nut when the flange is in place, if the front cover is off?

I've got all my bearings and seals now, just waiting for a good week or two to drop the axle.

-Darrell



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

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tr7v8mike Avatar
tr7v8mike Gold Member Michael Booth
SYDNEY, NSW, Australia   AUS
As of last week, my car also has a Quaife diff, so I'm happy to be a member of the Quaife Club. Just for a rare change, I applied Clint Eastwood's sage advice ..."I man's got to know his limitations"... and I sent the car to a diff specialist. I take my hat off to all of you who are able to do this yourself. I'm impressed.

tirebiter Jeff Garber
Dighton, MA, USA   USA
Not that I have a lot of experience rebuilding the later TR-8 differentials (I think the earlier ones were the same as the earlier TR-7 diff but not sure) but I have rebuilt several different makes/models of differentials and there are a lot of similarities. Then there is the extra nut that you tighten until the collapsible spacer has crushed just enough to attain the required preload of " 20lbf in " which I believe means the same thing as 20in/lbs

The Factory Service manual says to use 90 to 120 ft/lbs torque on the pinion flange to pinion nut.

I looked for an illustration of the service tool 18G 1272 but had no luck. That's the one you are supposed to use to tighten the larger nut. I'm assuming it looks like a box end wrench but has a severe offset to fit in, underneath the pinion flange. Put the tool onto the larger nut, then slide the flange over the splines and hold the flange by your favorite method. Another piece of bar stock bolted onto the flange works well. Tighten the larger nut underneath.

A socket wrench cut off short enough with a 1/4" X 2" X 18" solid steel flat bar welded across the cut end of the socket, would probably suffice for doing the job. Drill a large hole in the bar for the pinion to go through.

I'm assuming the larger pinion nut is recessed just enough to prevent using a regular box-end wrench. By looking at a parts illustration it looks like you might be able to tighten the pinion flange onto the pinion and still be able to tigthen the larger nut with the 18G 1272 service tool you made.

I don't have one of these diffs in front of me so I cannot say if any of this is possible but maybe it will help you figure out what to do. Maybe somebody else on here has an illustration of the 18G 1272 service tool so you can have a better idea of what it looks like. If needed I'm sure I could put one together for you just as I described, but you would need to provide some measurements first.

When you can't get the right tool, sometimes you have to make it.

added:

I found the illustration of 18G 1272. It's not at all what I was imagining. It is a two piece tool.

One piece has a hex hole that goes in, fits over the nut and has a flange that bolts to the diff case via the threaded holes which the front cover/oil seal housing bolts go into. The other piece has internal splines that engage the pinion splines and two ears with holes to engage it with an offset spanner (Service tool 18G 1205 same as RG421 apparently).

I guess the nut is held fast to the diff housing and you rotate the pinion to tighten the nut. Seems a little "British" to me but It doesn't seem to have a way to prevent the diff/axle housing from turning. I guess the size and length of the housing lends itself to this method instead of holding the pinion from turning while tightening the nut as I would have attempted with my home-made tool design. Also the factory tool allows the mounting of the in/lbs preload checking tool, to the flange bolt holes.



Edited 1 time(s). Last edit at 2017-02-19 02:07 PM by tirebiter.

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
Hi Jeff,

Thanks for the ideas. I see that you did find a picture of the factory service tool, but I'll attach it for others to see as well. I was thinking that you would use two special wrenches to hold each part, but you idea of it bolting to the front of the diff housing makes sense.

Given how shallow that plate is, I'm hoping a box-end wrench will have enough offset, we'll see.

1-7/8" wrenches are not cheap!

-Darrell



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


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tirebiter Jeff Garber
Dighton, MA, USA   USA
About $20 for a cheap no-name 6-point socket. Grind away the outside diameter if a standard socket won't fit into the depression, after you cut it short.

It looks to me like one of those places where it's tempting to get a partial bite wtih an offset wrench but where it will end up biting you in the you-know-where.

Either way, you'll need to use the flange to keep the pinion from turning. I would not stress the gear teeth to do that job.

Ya gotta love the way the illustration shows both pieces of the tool in the incorrect orientation ... or are they ?

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ROAR Mihael Rogers
Arroyo Grande, USA   USA
I'm noticing the same problem: when I come out of a tight corner and accelerate hard, the inside wheel spins. My approach is to go to a bigger Front ARB and crank some positive caster and negative camber if it plows, The plan is to move more roll coupling to the front and add neg camber when the car heels over in a tight autocross turn. Are there alternative higher diff gears for this rear end? I'm turning over 2500 at 70, should be below 2000, I can start out fine in 2nd.

I tried a LSD IN MY LOTIS 7 AND MY ALLERDETTE and both plowed until they came suddenly loose, probably too light tho some formula cars use them! I ripped them out!

tirebiter Jeff Garber
Dighton, MA, USA   USA
Darrel, Any progress lately ? Have to gotten the inner nut off yet ?

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darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
In reply to # 1440378 by tirebiter Darrel, Any progress lately ? Have to gotten the inner nut off yet ?

Hi Jeff,

Just started pulling the axle today.

-Darrell



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
As mentioned before, I pulled the axle today, cleaned it up a bit, and started to tear it down. The 1-7/8" box wrench I got will only engage the big nut about halfway, and the "deep" socket (which wasn't very deep) won't even engage. So I'll be fabricating a tool. Need to decide if I want to cut the box end off of the wrench (which is 12 pt), or cut a section off of the socket (which is 6 pt). If I had a bigger welder (and really knew how to use it), I might be able to cut the handle off of the box wrench and re-attach it at the top edge of the box end. But I'll probably just weld whatever part I cut to some steel plate, and add a handle.



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


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tirebiter Jeff Garber
Dighton, MA, USA   USA
I vote for cutting the socket and welding a plate to it. Have you measured how much clearance there will be for the "handle to stick out from underneah the flange ?

You might want to farm this out to a shop with a good band saw that will cut it straight (or do it on a lathe) and has a 150 AMP welder. Then they can make up a large disc to weld to the outside and you can drill holes to mount it just like a Churchill tool. Or weld a long flat handle on at exactly 90 degrees, yourself.

Not at all surprised the thick handle of the box wrench is in the way. I'd be willing to bet an offset one wouldn't fit either.

You might be able to grind enough meat off the box end wrench where the handle attaches. Grind just enough to allow it to go into the hole all the way but not weaken it too much. Still, you end up with a funny angle to tighten and crush the collapsible spacer and hopefully clear the flange, while doing so. Or take it back for a refund.

It's probably going to take quite a bit of grunt to collapse the spacer. Probably in the order of 150-200 ft/lbs. I doubt you'll have to put anywhere near that much into it to loosen the nut, however.

I personally don't know of any other car or truck that uses this inner nut deal. Is it common on some other makes ? I've never seen anything like it. Makes for a quick and easy seal replacement.

darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
I'm going to try to sort out the wrench situation later today, I'll let you guys know what I come up with. I did find this wrench that I think would work:

Stanley Proto J2630SW Heavy Duty 12 Point Offset Striking Wrench 1-7/8 Inch

I check the backlash, and I'm only seeing 6 thousands, which seems on the low side.

The carrier slide out with no prying, and I'm seeing 4 inch-lbs preload on the (used) pinion bearing. So regardless of installing the Quaife, it looks like I needed new bearings!

I played with gear marking compound before I removed the carrier, just to see what it looked like, pictures attached.



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


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darrellwalker Darrell Walker
Vancouver, Washington, USA   USA
1966 Triumph TR4A "Christy"
1981 Triumph TR8 "Kate"
OK, got my tool built. I cut the box end off of the giant wrench, then ground the stub off enough to clear the diff housing, and welded it to a 2" x 3/16" plate (had it laying around). Not the prettiest of welds, but I put it in my bench vise, pulled as hard as I could on the 1 ft long plate, and it held. I also whacked it against the anvil on the vice.

Not bad for a 110v welder, which I couldn't even crank up to full power, because I had thin wire in it. An someone that knows next to nothing about welding!

I can add a longer handle if I need more torque.



Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA


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tirebiter Jeff Garber
Dighton, MA, USA   USA
Yes, I agree. About a foot pound less than like-new pinion bearing preload should be addressed. I wonder how quickly it wears to that point with new bearings though. Even the most expensive bearings I've ever purchased still have some very tiny (micro-small) surface irregularities that wear down initially, once put into use. I suppose NASA specifies bearigns tha are already so finely polished to the point that they are 100% broken in before ever rotating.

Because of the angle of the rollers, the amount of wear that happened to reduce the preload by about 12 in/lb, is extremely small. I would be surprised to find that the surface hardening was jeopardized. Once you have your 1-7/8" wrench figured out, Try to see how far the nut needs to be rotated to get to the specified preload. You might be surprised at what a minute amount, the nut needs to be tightened. In other words how very little more, you need to crush the collaspsible spacer.

What are you referring to for a specification for the backlash ? You say it seems small but can you find any hand engraved numbers indicating what it was when the two pieces were matched up during manufacturing ? In my expereince, the gears need to be absolutley spotlessly clean and dry to make out the numbers.

I bet the offset wrench would be too thick behind where the handle attaches. It will not go in far enough either. I still say cutting a socket is the way to go. Even just torching it off and using the same torch to weld it to a wide, flat handle would be plenty strong.

http://www.northerntool.com/shop/tools/product_200654007_200654007




Meanwhile ...

The contact pattern looks like it's certainly large enough and well-centered but too close to the edge of the teeth in my opinion. Did you get any shots of the pattern on the pinion teeth ? The pinion gear may need to be lowered a little to expose thinner teeth near the small diameter, so they will contact deeper on the ring gear teeth and retaing the proper backlash.

As you rotate the pinion, restrain the ring gear by hand to squish out the marking grease. Try to make a make a clean pattern in one pass. I usually only mark about 7 or 8 teeth at the beginning stages. When I think I have it all correctly setup, I mark them all to make sure. I assume you checked for runnout before doing any of this.

This is where you'll need to wory about the pinion bearings since the shim to adjust pinion height goes between the bearing and the pinion gear teeth. The bearing will have to come off and go back on, to recheck the pattern. Sometimes over and over again.

Reuse the old bearing rollers with the new bearing cup to do the measuring/remeasuring and assume any wear on the rollers is negligible. If you can't get the pinion bearing off intact, you'll have to buy a sacrificial bearing and grind a little out of the ID so it is an easy sliding fit onto the pinion shaft. Make sure it is identical in every way to the new bearing you'll end up installing. Or make up a dummy spacer that will also allow the pinion to rotate, for checking the pattern.

There's a reason not many mechanics want to get into differential rebuilding.

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