[jwandhistools]

Long story short:

1986 SPG 5 speed

The roll pin on the shift selector rod came out, fell into the differential and took a tooth out of the ring gear.
The pinion suffered no visible damage.

I have a donor trans from an 87 with a good diff, and a busted transfer case.
Already have it apart.

According to the tranny info page on fixmysaab.com, they are the same ratio.

What is the wise move here, if any:

1.Use only the ring gear from the donor trans?
2. Use the entire differential assy including inner drivers from the donor trans?
3. Something else?

Not being a tranny guy, per se, I want to keep this a simple as possible.

Help, tranny gurus!

 

[nutcase]

The pinion and ring are matched pairs and must be kept together at the same location (you need to measure the mesh point with a dial gauge before dismantling the spare and match it into the box you are using.

 

[Jim Mesthene]

Sometimes they work OK for years with a single tooth missing from the Ring Gear.
If you do anything other than what nutcase suggests, it will be noisy. Correct Pinion depth is etched on the end of each Pinion Gear, Differential Carrier Bearing pre-load and Ring Gear backlash are the same for all.

 

[jwandhistools]

Don't I pretty much have to gut the entire trans to swap the pinion?
I can handle it, if I have the procedure.
I want to put this 86 SPG back together the right way, 1 time, so the trans is a big issue.

 

[Jim Mesthene]

Don't I pretty much have to gut the entire trans to swap the pinion?

Yes elkparts

 

[Jim Mesthene]

Don't I pretty much have to gut the entire trans to swap the pinion?

Yes.
It's not easy to measure Pinion Depth without the Special Tool to mount the Dial Indicator.

 

[mmoe]

Long story short:

1986 SPG 5 speed

The roll pin on the shift selector rod came out, fell into the differential and took a tooth out of the ring gear.
The pinion suffered no visible damage.

I have a donor trans from an 87 with a good diff, and a busted transfer case.
Already have it apart.

According to the tranny info page on fixmysaab.com, they are the same ratio.

What is the wise move here, if any:

1.Use only the ring gear from the donor trans?
2. Use the entire differential assy including inner drivers from the donor trans?
3. Something else?

Not being a tranny guy, per se, I want to keep this a simple as possible.

Help, tranny gurus!

Is the main case containing the first 4 speeds from the donor transmission still intact (as in not cracked and not disassembled)? If so, the most logical approach I can think of is to take the transfer case from the bad ring gear tranny and transplant it to the good back end.

The tolerances of the pinion location are +/- 0.05mm. Without the special measuring tool there is little chance you would get the location properly within tolerance.

PM sent.

 

[jwandhistools]

I have it apart. It lost a chain and cracked the transfer case, but the rest of the gears are all very sharp w/no chips missing at all. View attachment 16454

View attachment 16455

View attachment 16456

If I get enough info, I can put it back together with a new transfer case. Got lots of those. 2 of those spare trannys sitting there have toasted gears anyway.