9.5 ff regear

[No worries]

This is my first post so hopefully it is in the correct forum.
I am regearing to 4.88 in a 97 fj 80 rear using the stock carrier with Yukon gear set. Saving for the locker later but for now the 4.10s with 35s are killin me.
Is it typical for the 3rd to need clearancing for the ring gear? I figured it would be all over this site if it was typical but I haven't found anything about it.

Thank you for the help.

 

[Broski]

No, something is not right

 

[Broski]

Welcome to the forum.
Unless your has be part timed you need to do the front and rear regear at the same time.
And if it's a north American 97 then it's a FZJ 80

 

[No worries]

Welcome to the forum.
Unless your has be part timed you need to do the front and rear regear at the same time.
And if it's a north American 97 then it's a FZJ 80

Doing the rear axle swap in a 91 FJ for the full float and disc breaks. I have a spare 3rd, for the front, that I am building on the be bench. I plan to get the rear done and just install new 3rd up front.
Could it be the stock carrier? Most people seem do locker at the same time as regear.

 

[Railwelder93]

Yes it can be normal. I can’t remember if it was the front or the rear, but I did have to clearance a housing in that location on one when regearing to 4.88.

 

[azngarage]

I dont know about the stock carrier and 4.88 gear. But when i did my 5.29 with the tjm pro-locker, i have to trim the housing about quarter inch.

 

[Railwelder93]

Found a picture, it was the rear.

 

[No worries]

Found a picture, it was the rear.
View attachment 3051966

Ok i am proceeding with a grinder and a little caution... that something doesn't seem right.
Thanks for the pics. That ring gear looks alot more in the center of the groove than mine is looking, but grinding is grinding.
Do you guys remember if you added any shims to the pinion gear?

 

[abuck99]

4.88 Yukon gear install video by otramm

Might help

 

[Rusty Marlin]

I didn't need to add any shims on the front, the OEM shim was spot on. I did have to add some to the rear.
I didn't have to grind on the housing, and did add the lockers at the same time I re-geared.
The location of the ring gear will move closer to center as the ratio increases, as the pinion is getting smaller in diameter. So needing to trim some off doesn't surprise me, there are tolerances in everything.

 

[No worries]

Found a picture, it was the rear.
View attachment 3051966

I have watched that video a few times, it has been helpful. I did my best to build a bracket for the engine stand like the one in the video.
With minimal grinding, about 1/8 of an inch on the top of the 3rd I was able to pull a pattern. I think I'll need a little more in the long run for better clearance but atleast I was able to get a pattern.
Stock pinion shim +.050 was to deep looks like I'll be pulling it trying just the stock.
Thanks guys for the confidence to break out the grinder. Its hard to put back on material after its gone.
Let the adventure of getting the perfect pattern begin.

 

[abuck99]

If it were mine, I would clearance that more.

 

[Railwelder93]

Yea there is plenty of meat there, don’t be afraid to give it a little room to do it’s thing.

 

[Railwelder93]

That picture I posted is post grinding, and at a bit of an angle. I believe it probably looked pretty similar to what your looking at on yours before clearance.

 

[cvenom96]

Little bit of a thread hijack but I have a quick question. My 96 has open front and rear diffs. I ordered 4.88 Nitro's. Just went to install the front ring gear and the ID is way too big for the carrier. My OEM ring is roughly 4.94 while the new Nitro is about 5.25. Can anyone verify that the 4.94 is correct for my truck and not something wonky going on? I specifically said I had an open front when I emailed with the vendor as to make sure I got the right ones.

 

[Railwelder93]

The ring gear should be a tight fit on the carrier. You definitely have the wrong gear if it fits loosely.

 

[Broski]

Little bit of a thread hijack but I have a quick question. My 96 has open front and rear diffs. I ordered 4.88 Nitro's. Just went to install the front ring gear and the ID is way too big for the carrier. My OEM ring is roughly 4.94 while the new Nitro is about 5.25. Can anyone verify that the 4.94 is correct for my truck and not something wonky going on? I specifically said I had an open front when I emailed with the vendor as to make sure I got the right ones.

I would send them back.
I well not run anything Nitro on my rig.

 

[Atomic City]

Late to the party for the OP, but I had to clearance my rear 3rd for my yukon 4.88s.

 

[cvenom96]

Yeah determined they were definitely the wrong gear. Vendor is shipping a new set out.

Why no Nitro? Once I get the right set I'll let you know if I had to clearance mine for the 4.88s.

 

[Broski]

Yeah determined they were definitely the wrong gear. Vendor is shipping a new set out.

Why no Nitro? Once I get the right set I'll let you know if I had to clearance mine for the 4.88s.

Cheep Chinese junk and really bad customer service!! Right now you have a good reason to just return them.