128 replies to this topic

[StarquestRescue]

This 4.62 pinion has the #382 on it. Dial gauge indicates 1.900 from bearing center line to pinion. Plan is to measure the used 3.90 set before i disassemble it and than get the same measurement in the starion housing and than set backlash and check pattern.

The problem is the 4.22 gear set is new and i don't have the luxury of using the dial gauge reading as a starting point. Can the correct dial gauge reading be calculated from the # i hope to find on the 4.22 pinion? The 4.22 starion rear is already assembled by a previous owner but has never been run. The preloaded are that tight we can barely turn it. I will check the pattern before i proceed.

Do the pinion bearings interchange between the the truck and starion rears?

Any pointers from those who have do the swap. I assembled Mack truck rears years ago so i do have some experience with gear set up.

Thanks

Edit/update

Early on i thought the pinion depth gauge would minimize the trial and error. I had the 3.90 pinion in two different starion housings and it was telling me the 3.90 sat .035 lower than it did in the truck housing. I rolled the dice and added the .035 to the original shim. It was not even close, way to many shims. I then tried the original starion housing .065 shim (truck housing shim was .064). That was to little, went to .075,that was to much. Ended up at .069. In all 9 pinion shim changes.

When i put the new bearings on and it threw of the pattern, the gauge would have given me an ideal how much, but i had not taken a reading before the change. Repeat ability with the gauge was good in the same housing. I don't know where the error came from.

Edited by StarquestRescue, 19 August 2009 - 04:20 PM.

[Chad]

It's been said that the 4.22 is the higheset numericaly that you can go, and that the 4.22 is a difficult fit.  I have a 4.22 ring/pinion NIB in my closet if you need some measurements.

there is a FAQ post that has the all the mitsu donor cars and some compatibality info in it, not a specific answer to your question, but you may be able to compile the info you need out of that FAQ post.

[Richie_Rich]

Check out:
http://www.ringpinion.com/HowTo.aspx

[Shelby]

pinion depth is adjust'd with the thick spacer behind the large pinion brg, it is spacific to the houseing NOT the pinion use'd , it's been a long time sence i was thru chyr's diff school class but i was told that the machineing of pinions is to a VERY close tollerance , and if there was any veriation from "0" it was stamp'd on the pinion face, where you see your numbers , i see no + or - numbers so i'd asume the depth adjustment to be "0" that would mean reuse the same spacer that is in the houseing already ,,again asumeing that it IS THE ONE belonging to that case houseing

pinion brg preload is set by use of the small shim spacers behind the smaller frt brg , too tight you need to add a slightly thicker shim ,, some diffs use a crush collar , mits did not , do so carefuly a little goes a long way

also with the mits lsd diff you need to keep the back lash to the low side as there is no way to preload the diff side gear brgs , they alow for the tourqe thrust durring diff operation ,meaning if the alow'd back lash is .004 - .008" stay closer to the .004 " if makeing changes , the actual back lash will gain slightly durring heavy tourqeing

also always replaceing side gear brgs is not always nessarry , good brgs are good brgs,, how ever with out changeing any shims you can gain a little less back lash by replaceing the old side gear brg on the ring gear side this will ever so slightly move the ring gear closer to the pinion lessening the back lash a thousands or more ,, new brgs
on both sides should keep every thing exactly where it is now

seting up 3 diffs with 3:90's i reuse'd all old shims and spacers and back lash on all 3 were .004-.005" only new brgs were the large pinion brg due to haveing had to press the old ones off the old pinion to get the houseing spacers

Edited by Shelby, 02 October 2008 - 11:15 PM.

[StarquestRescue]

I got some good replys from the guys on the 4x4 wire as well http://www.4x4wire.com/forums/showflat.php...=14&fpart=1

The number etched on the pinion will be the variation from standard height.
Refer to the gear you are removing to get the variation in setup height.
From the early 80s Mitsu reduced dependency on the pinion markings though and just uses gauge blocks to select the pinion shim.
This procedure leads one to use the shims that came with the original housing to set height. This has been working well with the setups I have been doing.

With that tight 4.22, I would drop the ring gear out and investigate if it is the pinion preload that is tight. Might be that the seal is dry? It might be the diff preload that is tight.

You will love the short gears in a Starion, I run 4.22 at some roadcourse events and 4.62 at AutoX and hillclimbs.

While you are in there check the stack in the diff clutches. Many of them come ABBA, if you swap the inner and outers to ABAB you get a stronger lockup.

In my experience, the shims are used to rule out (mostly)housing differences, and not gear differences. I always start with the old shim measurements as a reference for pinion depth.

Started disasembly of my starion rear. Pictures are of my 3.54 rear.

Edited by StarquestRescue, 05 October 2008 - 03:00 PM.

[StarquestRescue]

I found problems in my friends 4.22 rear. It was to tight and i didn't like the pattern. This was in a general automotive shop twice. They are 0 for 2.

Bearing cap on wrong.


Cap on correct.


Damage to cap from being put on backwards.



Shim was not in right.


Shim on right does not belong in this rear. Smaller diameter, no wonder we could not turn it by hand. Was against the bearing cage not the bearing cup.

[Shelby]

man thats some  very basic screw ups,,makes you wonder  if they  put the right houseing spacer  on the pinion

i would hope you made the owner of that shop aware of what  sort of quality work  his shop turn'd out

[StarquestRescue]

Any one know what the standard 4.22 pinion shim thickness is?
The shim kit ranges from .055 to .065 with one .012 shim.
The 4.22 pinion on the right seems to have way more shims than the 3.54 on the left. I believe the pattern is telling me the 4.22 pinion is to close to the ring gear center line.
We ordered a shim kit for a starion rear

[Shelby]

there is no reason to guess at pinion shims,,, shims are for the houseing you KEEP the shim with the  houseing  it was in
so what that means is you pull the large brg off the pinion  that came out of the diff houseing your useing take that shim and use it on the NEW pinion, that means BOTH pinion brgs have to be pull'd off the pinions and a new brg  install'd useing the correct houseing shim,,(the one for the houseing your useing )

to get the proper houseing  shim from scrach you will HAVE to use the factory set up tools , and they are hard to come by after 20 yrs

[Richie_Rich]

Unless you have the right pinion depth setting tools, you should start out with the shims used in the housing and do  a swipe test.
The problem you are going to have is the pinion bearing is pressed on and it can be difficult removing without damaging it.
They make bearing tools, but they are expensive.
When I did the gears in my Durango, I used a split bearing tool with a gear puller and was very careful.

To do it right, you may have to mock up and pull down the setup several times to get it perfect.
The rear of my Durango was easy.
The front was a different story. I probably pulled it down a dozen times.
I ended up not using any shim under the pinion and the factory shims for the carrier.
I think it's Randy's that sells a DVD for setting up rear ends. It's very good.

[Chad]

http://www.drivetrain.com/ringpinioninstal.html

Not too wordy, but lots of good info and illustrations.

Perhaps round up a few differnet diff housings, find a housing that fits yoru gears better?

I've been told by those whom have done this succesfuly that it's a difficult fit so don't take it personlay.

Any year LSD housing will work, they are the same 83-89, the only difference is in the clutch pack where the splines are differnet for the different CV shaft diameters.

[Shelby]

one more time the houseing has to use the shim that  is behind the pinion that came out of it,, and yes  you will need a new  pinion brg,, but they sell for arround $15 so it's no big  deal

every time you change the pinion you HAVE TO  PULL THE  BRG OFF THE OLD PINION SO IT CAN  GO ON THE NEW PINION

THE SPACER STAYS WITH THE HOUSEING ,,,NOT THE PINION   GEAR

this is true even if your throwing away the  old ring and pinion, you HAVE to keep the spacer thats was on the pinion you  took out of the houseing your gona use

if the pinion your gona use has a brg and spacer on it,,REMOVE the brg and the spacer
install the spacer  that was in the houseing your gona use and a new brg

[StarquestRescue]

Some quotes fom my first post.

I assembled Mack truck rears years ago so i do have some experience with gear set up

The problem is the 4.22 gear set is new. The 4.22 starion rear is already assembled by a previous owner but has never been run.

There for i don't know what the original spacer size was. The patteren is telling me there are to many shims in there.

Not much to report. Parts have been ordered. and i am digging through my puller selection. I should be working on it now but i turned on this damn computer. Thanks for every ones input.

[StarquestRescue]

I am going to set the 4.22 aside and work on the 3.90. I disassembled the 3.90 truck donor rear and documented backlash, pinion depth and gear pattern. Now i need to pull some bearings, swap spacers and press bearings back on.

Measuring the backlash and pinion depth.




The 3.90 donor pattern before disassembly. They don't get much better than this.




The all important note book.


The three bears. 3.54 on the left, 4.22 center and 3.90 on the right.

[Shelby]

you are right thats a  not to shabby  pattern,, but  one thing i have learn'd about this diff set up on the quest is the  drop in carrier ,it has  no way to actualy preload the side
gear brgs except for  while they are under load and heat expantion of the  metal
most  diff's you'd be  good with that pattern ,because you can adjust the  side  gear brg  preload by one means or another
but my   guess is  the pattern will move toward the outter edge of the ring  with  heavy  tourqe load , how much drag  did you place on the  ring when you  made your pattern  
with  only .005" back lash  i say  try it and see .004" would  make me feel better

these  diff are not  a real noise maker any way due to the way they  are mount'd
the early 70's  chyr drove us crazy with  a 42 mph gear whine trying to use 2:76 and 2:90  gear ratio's

question  how did you come up with a spacer thickness,, did you go by the 3:54 pinion  depth and set the 3:90's to the same or did you just go with the spacer on the 3:90's

[StarquestRescue]

Shelby the pattern in the picture is what the 3.90's gave in the truck housing. I was not able to get much load on it.

The install is still in progress. I test fit the 3.90 pinion with the truck bearing and spacer still installed in the starion rear and it sat at the same height the 3.54 had. (.035 lower than i figure it needs to be).

I pulled the truck bearing off  the 3.90 last night but the spacer i used to extend my puller draw bolt beat up the pinon end and puller bolt. I need to try some thing different. The bearing did suffer some cage distortion as well.

The part # for the truck bearing and starion bearing are different but they look the same so far?

I have a starion bearing on order, but i need to find a cheaper source when i get one off and can see the numbers on it. I don't have press here and work 10 hour days monday threw thursday so i probably wont get much done till next weekend.

I like the ideal of setting the back lash a little tighter to allow for shift under load.

[Shelby]

i have  just walk'd into our local napa and  pick'd up  all 3 of the pinion brgs i have need'd,one pre 88 and  two 88/89,all were arround $15 ea and  your always  gona damage the  brg when  pulling ,so plan on replaceing the brg

[StarquestRescue]

In to the LSD now.
The stack as installed at the factory.

Plate, plate, spring plate, spring disc, plate, disc.


I am going to remove one of these the friction plates.


And add one of these friction disc and change the stack order.


A damaged 4 bolt LSD is donating its friction discs. You can see some of the debris and scars from a snapped axle.

[Shelby]

any progress to report on this

[JustPaus_88TSi]

Man.   Is it wrong to feel fine/confident about jumping into tearing down and rebuilding motors, but having serious doubts about rearends? lol


Haztoys mentioned that damn near all of the stock SQ rears he saw were set up wrong from the factory.  His statement didn't make me feel better about tearing one down at all.  haha