high pinion 3rd member?
 

so.. i have a few questions about putting a high pinion 3rd member into a stock "front" housing. the reason for this being i need better "driveline angle" to get rid of my vibration caused by having a single t-case and a low pinion 3rd and 5" of lift. here are a few questions i need help with, any help would be great.
Thanks, Mike


1. will a high pinion 3rd fix my problem?
2. what kind of housing modifacation if any? will i need to do to fit a high pinion 3rd into a stock housing?
3. how much money should a stock a high pinion 3rd member cost?
4. would i have to get new/different axels to accomidate a high pinion 3rd?

i cant stand this vibration any more!:bang:
any help would be great thanks!

It may help some but still youll get vibrations. Do you have a double cardon cv in the front shaft? What is the year/ model? Is it a solid axle or IFS?

As for new axleshafts which I think you mean NO
The 8" thirds will fit in any 8"axle granted if you get an elocker you will need to modify the housing a bit to accomidate.

The high pinion help also with ground clearence but its a small gain. Dont ever put one in the rear unless its a ford 9". Ide say check to see if your front driveline is CV or not and if not change it too and the vibrations should stop some

ya its a cv driveline, i had a single cardan drive line in there before and it was worse so i swapped it for the cv style, that helped but its still pretty bad.

as for my truck it is a 91 standard cab shortbed sased 5 inches of lift
stock gears

Sorry dude not much is going to help with a big lift, tires and speed. Keep the speed down (even if you are) and since you built it to wheel it sounds like your gonna have to live with the ride in this case. Hell driving on rocks and through mud cant be much worse can it??? The high pinion may help a bit but youll always have a vibration in the front

the funny thing is it dont vibrate at all unless hubs are in and im in 4high or 4lo. but if hubs r in and im in 2 wheel drive i can do 60 and its smooth but as soon as i engage both it starts and it vibrates pretty bad at like 10 mph

so cutting and turning knuckels to fix the vibration is my only option?

Strange its not in 2wd hubs locked.

Cut and turn would do it.

You may be able to shim it a little.

4crawler.com has shims.

http://4crawler.com/4x4/ForSale/Shims.shtml

Beware the death wobble though. If you get your caster too far out, you could have issues. Roger should be able to help you a little.

duals help alot. And hey why not. what a great excuse to get duals. And hey, if it doesn't solve the problem, well damn you have duals.

I can do about 40-50mph with mine.

thanks ike, i already have 3 degree shims can i go more with out getting the deth wobble? yes its wierd i can also put my front end at max droop and it stil spins smooth, but anything over like 10mph with 4wheeldrive engaged it gets pretty bad:bang: . so what do u guys think would b the best option.

1.cut and turn?
2. high pinion diff?
3. double t-cases?

whatcha got a dune racer or sumthin?

haha no i use my tacoma for that!

Cut and turn is a bitch dude. I've watched a guy I'd consider to be a master fabricator do his 40. Took FOREVER. Built jigs, and tig welded the beast. Its dead on, but whoo. To me, thats the last resort.

Here's my advice:

First of all, duals are awesome. I'm in the middle of my dual install, but I've watched enough in action to know that you'll be blown away.

Second, HP diffs are stronger, and you can get it with an elocker. Hunt junk yards for FJ-80's. The fronts with lockers are HP set up, and, if you get it right, you could have it for as little as 300 bucks, needing only a refurbish.

If you do both of those, which will benefit you greatly regardless of the vibration, and, hopefully, will solve your issues.

If you STILL have the vibration, then start shimming more. The amount of shim you can do varies from axle to axle. If you can't get it to go away without deathwobble, cut and turn.

Anyway, just they way I'd look at it.

thanks ike, im looking at it the same way. i think il start with a lil more shiming. and i will be looking for a junkyard jewel "highpinion 3rd". ill shim more tomarrow then post the results! wish me luck:pop:

FJ-80 diffs are for 8"? I thought those were bigger axles? Shows what I know :chair:

Good luck man!!! Hope it gets solved.

Front diffs are 8. Rears are 8.875.

http://www.4crawler.com/4x4/4R_TechInfo.shtml

damn good info

I've a front HP 4.88 diff out of a Toyota LJ-70. It's bolt-on.

Helped a lot with the front DS angle. This is with the suspension extended:

http://img91.imageshack.us/img91/3865/dscf07541fe0.jpg

http://img356.imageshack.us/img356/2...cf09071cf5.jpg

http://img48.imageshack.us/img48/7789/dscf0812xw9.jpg

http://img143.imageshack.us/img143/957/dscf0815gv2.jpg

With the truck on the ground the angle is good, I had no vibrations but my front DS is balanced too.

David

ya thats what im lookin for got any 4 sale? lol, how much did the pinion actually go up? that measurement would be helpful to see if i need anything more than just a high pinion! thanks for your input blizzard!

just cut and rotate the axle for a better driveshaft angle cut it at both knuckles set your castor and reweld the knuckles back on and save the 1000 for the hp

ya it sounds easy but i no that it is above my head, i mean i can weld ok, and ive been known to turn a wrench or 2, but im making "cutting and turning" my last resort! and im hoping to find one for cheaper than $1000!
but thanks for your advice bigarms.:)

i got my hi pin for $50 with a toasted R+P on IH8MUD. Deals are out there just keep looking.