has anyone installed a thrust block on a rear 9.5"? (1 Viewer)

[Arya Ebrahimi]

Hmmm. You probably set up the 4.88 not long ago, in comparison to a "from the factory" gearset where there is a bit more slop in the bearings, and I suspect the two carrier bearing adjustment hubs were probably tighter on yours.

The second diff was one I grabbed off the mud classifieds, and other than a quick look over I never checked backlash with a dial indicator or preloads.

Im starting to think keeping your carrier bearings at least as tight as spec will help alot.

I'm certainly no gear expert, but what I learned from the mini-truck crowd is that carrier bearing preload is essential to getting diffs to survive in situations they weren't intended for.

For example, I believe factory spec for carrier bearing preload on an 8" is 90ft-lbs and the hardcore guys are running 200ft-lbs. They are also reducing the backlash from the factory spec of .08 to .04 or so. These changes seem to make all the difference.

I would suggest taking a read through a few diff builds on the following website. Zuk is well known for making Toy diffs live long abusive lives

www.gearinstalls.com

 

[cody c]

I'm certainly no gear expert, but what I learned from the mini-truck crowd is that carrier bearing preload is essential to getting diffs to survive in situations they weren't intended for.

For example, I believe factory spec for carrier bearing preload on an 8" is 90ft-lbs and the hardcore guys are running 200ft-lbs. They are also reducing the backlash from the factory spec of .08 to .04 or so. These changes seem to make all the difference.

I would suggest taking a read through a few diff builds on the following website. Zuk is well known for making Toy diffs live long abusive lives

www.gearinstalls.com

Thanks, I will have a read for sure!

 

[mookie]

Not sure if it was just a coincidence or ? But after i started preloading the carrier bearings like that link posted above suggests i started breaking rear axle shafts like crazy

 

[Arya Ebrahimi]

Not sure if it was just a coincidence or ? But after i started preloading the carrier bearings like that link posted above suggests i started breaking rear axle shafts like crazy

Were you breaking other things that lead to adding carrier bearing preload?

In other words, did the breakage shift from the diff to the shafts?

 

[mookie]

Were you breaking other things that lead to adding carrier bearing preload?

In other words, did the breakage shift from the diff to the shafts?

Not really, i just read that article one day then started doing it. I've broken a couple of coarse spline pinions over the years but that it as far as r&p goes.

 

[Josie'sLandCruiser]

Hi All:

Could someone please explain A) what a thrust block is, and B) what advantage there would be in adding one to a semi-floating Land Cruiser rear axle?

Thanks much!

Alan

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Im just in the process of rebuilding my rear third with new ring and pinion. This is the third one its seen in as many years, and Im thinking maybe a thrust block would give it a little more life.

Since I cant reassemble it till I get a replacement bearing (I broke part of the pinion bearing) and I have it apart, has anyone had any luck in doing this modification? Searched but couldnt find.

Thanks.

 

[peesalot]

In this case it would be a bolt threaded into case or somehow set up to keep the ring gear from deflecting away from pinion.

 

[cody c]

Hi All:

Could someone please explain A) what a thrust block is, and B) what advantage there would be in adding one to a semi-floating Land Cruiser rear axle?

Thanks much!

Alan

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http://www.truehi9.com/thrustblock2.html

 

[Shinichi]

On the short term fix of the 60 rear and stub shaft. Have you tried clocking it 90 to fix the vibration? Hopefully you get the 80 third sorted out and it's not an issue.

 

[cody c]

On the short term fix of the 60 rear and stub shaft. Have you tried clocking it 90 to fix the vibration? Hopefully you get the 80 third sorted out and it's not an issue.

No I havent tried that yet.

The vibe is still there but doesnt seem to be getting worse. I have the replacement pinion bearing on the bench with the rest of the third but have been procrastinating its reassembly. Ive been investing what remains of my energy at the end of the day into the hilux instead actually, and have been pondering if there will be issue with reusing the crush sleeve with the pinions or to go the solid spacer route.

I did grab some of the fancy bearing grade brass though for use with a thrust block bolt end, similar to whats in the fancy High 9 third member.

Maybe at lunch today Ill get down to the bolt supply and see if I can find a fine thread 3/4 bolt with a hex socket end, and a fine thread tap.

 

[notthejeepnomo]

Are you also using a solid pinion spacer?

 

[fj-rankenstein]

i have got a ton of 4.11 thirds on the shelf.. i think i have at least 8 or 9.. i have only ever ripped the pinion off of one of my thirds when i was still running a 2f, sprung over, no track bar and doing something dumb..
i have both coarse and fine spline pinions.. not sure of how many of each kind.. if you need a spare for cheap than just give me a pm.. it might be a quicker option to get you up and running while you are waiting for parts for yours all the time..

and i need an excuse to come up to Calgary this winter..

 

[69rambler]

Hope this is helpful, but there's no such thing as bearing grade brass. Brass would be a really bad choice for a high load bearing surface. One of many grades of bearing bronze would be a great choice for the application though.

Bronze good, brass bad.

 

[69rambler]

+1 for carrier preload as well. To me, broken gear teeth would have me thinking faulty setup, not jumping directly to the conclusion that the diff is weak. Crush sleeves certainly have limitations and solid pinion spacers are easy to find or make and install. They should be an automatic when you think you could be pushing the limits of a crush sleeve diff.

On a side note, a friend's employee is always talking about his good buddy Carl Jantz. Neat to hear his name mentioned and see his work.

 

[cody c]

Hope this is helpful, but there's no such thing as bearing grade brass. Brass would be a really bad choice for a high load bearing surface. One of many grades of bearing bronze would be a great choice for the application though.

Bronze good, brass bad.

Sorry, same color, seems the same to the metallurgy ignorant.

+1 for carrier preload as well. To me, broken gear teeth would have me thinking faulty setup, not jumping directly to the conclusion that the diff is weak. Crush sleeves certainly have limitations and solid pinion spacers are easy to find or make and install. They should be an automatic when you think you could be pushing the limits of a crush sleeve diff.

On a side note, a friend's employee is always talking about his good buddy Carl Jantz. Neat to hear his name mentioned and see his work.

Interesting, if you want to donate a well set up diff to see if it can withstand some clutch drops with 37's and an overfueled 6BT Id be happy to give them a try to verify . I think the crush sleeve's will need to be swapped in place of spacers as you say.

I actually havent done anything with the diff since I posted this, I still have the other third on the countertop taking up space dissasembled. Been busy distracting myself with things I shouldnt be working on...

 

[69rambler]

Interesting, if you want to donate a well set up diff to see if it can withstand some clutch drops with 37's and an overfueled 6BT Id be happy to give them a try to verify . I think the crush sleeve's will need to be swapped in place of spacers as you say.

It's good to hear that overfueled 5.9 Cummins clutch drops with 37" tires are the reason you're breaking parts. You'd break a Dana 70 doing the same thing.

Good luck with your next diff.

 

[cody c]

It's good to hear that overfueled 5.9 Cummins clutch drops with 37" tires are the reason you're breaking parts. You'd break a Dana 70 doing the same thing.

Good luck with your next diff.

Ok Thanks!

 

[mookie]

here's a load bolted LC 3rd

http://www.pirate4x4.com/forum/toyota-land-cruiser/1587993-tlc-9-5-jantz-load-bolt.html

 

[FL cruiser]

Hopefully I'm not getting off topic, but since i went diesel I've had teeth break off the R&P, the splitcase and the H55. And mine only has 260ft lbs of torque.

Maybe it's the torque pulses of our diesels that are rough on the teeth of our gears?

 

[mookie]

wonder if it's because of the turbo lag? spools up and then shock loads your drivetrain with a crapload of torque?