1987 YJ Transmission

jwemobile031

New member
Hey! I am new to this forum so I am not sure I am posting in the correct place. Please let me know if I am not.

I am trying to replace the transmission for my 1987 YJ. I'm not a mechanic, but my understanding is that it's a 4L, 6 Cylinder. I've tried a few different local transmission shops and haven't had any luck finding parts or a replacement. Any guidance would be very much appreciated.

Thank you in advance for your time!
Jeremy
 

GP NOIR

Hooked
The 4.0 wasn’t installed in the Wrangler until the TJ. The YJ used the carbureted 258 inline 6. Both engines use the same bell housing bolt pattern. Whatever transmission bolts up to the 4.0 will bolt up to the 258.

(It is common practice to replace the 258 with a 4.0. Some conversions use the 4.0 fuel injection. Some use a carburetor.)

In 1987, Jeep used the Torqflite A999 3 speed automatic, or the BA-10 5 speed manual in the Wrangler. The A999 is a durable transmission. The BA-10 is a weak design and not worth the money to rebuild or replace. If you have a BA-10, replace it with a AX-15 5 speed, NV3500 5 speed or better still, an NSG370 6 speed from the TJ.

The only real downside to the A999 3 speed automatic is it’s a 3 speed. A 3 speed works fine, but lacks an overdrive. Jeep used the AW4 4 speed automatic with overdrive in the Cherokee. It’s a tough transmission made by Toyota and can be fitted in the YJ. The problem is it’s a longer transmission and rear driveshaft will have to be shortened and the YJ driveshaft is already really short!

Other transmissions can be used, however special adapters are needed which complicates installation and adds to expense.
 
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