A/T - 125/125C ATF Leaking Past Front Seal

TSB 86-43 (Sept)

SUBJECT: 125/125C

PROBLEM:
Transmission fluid leaking past the seal, even after you have drilled the extra drainback hole behind the seal.

CAUSE:
Too much converter bushing to stator support clearance.

SOLUTION:
Do not use converters with more than .003 - .004 clearance. Check them carefully.

TOOL:
Here is how to make a "tool" for checking clearance.

Note
You will need two "tools", one for the THM 125, and one for the THM 125C.

Step 1. Find a 125 and 125 C Stator Support you are willing to cut in half. The bushing surface must be good, the splines can be bad.




Step 2. Cut Stator Support in half, as shown in Figure 1. Sand the shaft smooth, where it was cut.




Step 3. Use the new "tool", and a feeler gauge to check bushing clearance. (See Figure 2)