Yoshie and kerrsurf...

[gwh200]

I got round to buttoning up the H2 diff today...just wanted you to know I checked the lash.

[slobodan]

Did you borrow that camera?

[gwh200]

Maybe...

[BUSHWHACKER]

Why did you go to all that trouble, it'll be on the floor again next month!

[gwh200]

Well there is that.

when this came off...



it's all was left that was in one bit. The local commercial garage have accepted liability for the install 6 months ago. The pinion chewed a hole in the bearing race, and through a bit of the casing...it's all gone a bit oval.
I've offered nor implied ANY warranty, it's much to knackered in there.

[yoshie]

You are spending some amount of hours on those things lately mucker.
It's about time you got a new contract doing your real job.

When you coming back North

[gwh200]

You are spending some amount of hours on those things lately mucker.
It's about time you got a new contract doing your real job.

When you coming back North

Soon as brian.

[KERRSURF]

Excellent, I'll get the kettle on.

[davec170]

I got round to buttoning up the H2 diff today...just wanted you to know I checked the lash.

That's the strangest positioning of a DTI to measures crownwheel backlash I've ever seen!!!!
I take it this is an "in joke", as that gauge will tell you nothing of use. It is measuring neither backlash or end float. In fact, if you have movement in the direction being measured the cap bearings are shot.

[gwh200]

Yes Thanks smiley bloke. That position, is indeed an "in" joke directed at brian...but as you dont seem in the know about a Gm posi diff, i'll let you in the know. The ring gear has Many different mounting posistions, depending on where and what locking application it uses. It is extremely easy to not mount the ring centrically.The lovely people at GM though allow you a very generous0.0001 inch deviation from true. This allows the interior clutch to throw its dog gears forwards and outwards, and allows,just like measuring for lash, a little room for expansion when the locker is in. The locker itself is not circular, but slightly ovoid on this application. It generates an awful alot of heat if driven hard in this mode...so the fact that the ring gear may be out of true by 1000th of an inch allows, (and according to GM ) the side dogs, to measure ring speed and deviation. If it doesnt detect that the ring is turning, or it doesnt "see" (via what looks like an abs sensor) that there is some sort of lash, then it throws the lock off as a safety. got that.

Oh btw...the eaton locker used in the later h3's has a fully floating pinion and ring and diff carrier. There is movement built into the bearing carriers and caps...


Oh and btw, the excursions, all use a diff made by ford itself, and original;ly used ina fordson major tractor. its tolerances are extreme and it almost shakes itself to death above 40 mph sometimes...but with a 21 bolt diff, somethingd gotta be out of balance.

And... the lincoln town cars, use a bog standard 9.5 inch diff, with 8 bolts.
These have a fully floating ring gear a'la ford excursion. there is a huge diff bowl on the back to allow said movement..

[davec170]

So, It is a joke then.

What are you measuring there then?

If it's concentricity of the ring, fine.
Now, educate me. if the measurement you are taking there is out of limits, what do you do to correct it?

Thanks for the snotty reply to a serious, well meant question.

I look forward to your answer with interest.

[yoshie]

Yes Thanks smiley bloke. That position, is indeed an "in" joke directed at brian...but as you dont seem in the know about a Gm posi diff, i'll let you in the know. The ring gear has Many different mounting posistions, depending on where and what locking application it uses. It is extremely easy to not mount the ring centrically.The lovely people at GM though allow you a very generous0.0001 inch deviation from true. This allows the interior clutch to throw its dog gears forwards and outwards, and allows,just like measuring for lash, a little room for expansion when the locker is in. The locker itself is not circular, but slightly ovoid on this application. It generates an awful alot of heat if driven hard in this mode...so the fact that the ring gear may be out of true by 1000th of an inch allows, (and according to GM ) the side dogs, to measure ring speed and deviation. If it doesnt detect that the ring is turning, or it doesnt "see" (via what looks like an abs sensor) that there is some sort of lash, then it throws the lock off as a safety. got that.

Oh btw...the eaton locker used in the later h3's has a fully floating pinion and ring and diff carrier. There is movement built into the bearing carriers and caps...


Oh and btw, the excursions, all use a diff made by ford itself, and original;ly used ina fordson major tractor. its tolerances are extreme and it almost shakes itself to death above 40 mph sometimes...but with a 21 bolt diff, somethingd gotta be out of balance.

And... the lincoln town cars, use a bog standard 9.5 inch diff, with 8 bolts.
These have a fully floating ring gear a'la ford excursion. there is a huge diff bowl on the back to allow said movement..

[davec170]

PS. I thought the Hummer diff worked on the Torsen principal. Is the one You've rebuilt a locker?

[davec170]

Yes Thanks smiley bloke. That position, is indeed an "in" joke directed at brian...but as you dont seem in the know about a Gm posi diff, i'll let you in the know. The ring gear has Many different mounting posistions, depending on where and what locking application it uses. It is extremely easy to not mount the ring centrically.The lovely people at GM though allow you a very generous0.0001 inch deviation from true. This allows the interior clutch to throw its dog gears forwards and outwards, and allows,just like measuring for lash, a little room for expansion when the locker is in. The locker itself is not circular, but slightly ovoid on this application. It generates an awful alot of heat if driven hard in this mode...so the fact that the ring gear may be out of true by 1000th of an inch allows, (and according to GM ) the side dogs, to measure ring speed and deviation. If it doesnt detect that the ring is turning, or it doesnt "see" (via what looks like an abs sensor) that there is some sort of lash, then it throws the lock off as a safety. got that.

Oh btw...the eaton locker used in the later h3's has a fully floating pinion and ring and diff carrier. There is movement built into the bearing carriers and caps...


Oh and btw, the excursions, all use a diff made by ford itself, and original;ly used ina fordson major tractor. its tolerances are extreme and it almost shakes itself to death above 40 mph sometimes...but with a 21 bolt diff, somethingd gotta be out of balance.

And... the lincoln town cars, use a bog standard 9.5 inch diff, with 8 bolts.
These have a fully floating ring gear a'la ford excursion. there is a huge diff bowl on the back to allow said movement..

You presume a lot about my knowledge of posi drive diff's/lockers.

I'm on a quest for knowledge, for knowledge is power.

You "appear" to have knowledge.

What diff' is in your picture? You state that you are about to "button up" the diff on an H2.



Can it do this: "This allows the interior clutch to throw its dog gears forwards and outwards, and allows,just like measuring for lash, a little room for expansion when the locker is in. The locker itself is not circular..."

Is the quoted bit above relevant in anyway to your picture?

Is it even a locker?

Please feel free to browse Google and get back to me tomorrow.

[gwh200]

You presume a lot about my knowledge of posi drive diff's/lockers.

I'm on a quest for knowledge, for knowledge is power.

You "appear" to have knowledge.

What diff' is in your picture?

Can it do this: "This allows the interior clutch to throw its dog gears forwards and outwards, and allows,just like measuring for lash, a little room for expansion when the locker is in. The locker itself is not circular..."

Is it a locker?

No presumption implied. This is indeed a locker. Its got forward and side facing dogs. The forward facing dogs engage the planet gear on the near side. The side dogs engage the toothed bit under the ring gear, behind the diff carrier. Its not circular, but oval. the actuator is held in place by a large spring, bolted to the actuator and a recess in a bearing cap.. the rear of the planet gear is ovoid in shape, the gears themselves are of course circular. The reason for the odd shape is to firstly accomodate the locker anterior to the planet gear, and also to produce the pulse required for the sensor to pick up its actually engaged. It requires two pulses, one from the plabet gear and one from the ring gear. aiaf it picks up a pulse, it asssumes all is well. If it gets too hot, or it thinks its not running (as in much to perfectly, and no "lash", then it disengages. It requires this to be fitted and running otherwise it throws a total wobbly and informs the gearbox ecu all is not well and sends it into safety, straight into 2nd gear only mode. Its an american idea borne of years(i should imagine)of not being able to do something simply, when there's a much more complicated way getting there.


The diff is made by John Deere. There are, so i understand, about 30 choices of diff for an H2. They are though, not at all man enough for the job once the conversion has been done(conversion being, another 20 feet of body, chassis etc added). Ther body builder changes various things, They leave the standrd hummer gearbox in place (BIG mistake) but put in a 21 bolt, 3.73 9.5"inch (10.5 in the 200 inch variant) tractor diff. This is because the torque from box is now transmitted down 5 or 6 bits of prop,via a half ton electromagnetic retarder. By the time the torque arrives at the diff, its moment of inertia and its angular momentum is perhaps 200% more than if it was standard...tail shafts and diffs were regular casualties till about 2003. The new system of bigger stronger everything was started and its quite a rare failure nowadays...unless the driver is a lunatic, as happened here...mind you he got 0-60 in 7 seconds flat from a 7 ton limo.

All i can suggest is that you yourself go browse google...perhaps watch some bare naked ladies getting it on, because your presumption and inference has apart from making all of us laugh here, is now making me bored. If you browse google for your answers i can only suggest, you may want to actually get under this specialist vehicle, fitted with bespoke transmission...oh you cant..oh your opinion..well we'll just carry on ignoring it. When you know what your talking about, instead of barging in with an unwarranted and ill informed comment come back, till then, butt out.