I am having trouble with my M5OD transmission leaking oil. I didn't catch it in time and the forks went bad because of this.

Would I be better of getting a used transmission from a salvage yard and then put new seals in it
Or should I just replace the forks in the one I have and put new seals in it to stop it from leaking and causing further damage?

Which would be a better decision.

 

It depends on the cost of the repair on the one that needs the shift forks and seals.
I just rplaced 1/2 shiftfork, 3/4 shiftfork,the seal for the top cover plate and the 6 plugs that
Go into the top cover plate to for $135.00 and installed it my self. I don't know what a used transmission cost? This there any other damage to your transmission from
Leaking the oil out? You will have to way your options between your tranny and
A used tranny!

 

Ive replaced the forks before and it was a hundred for both forks. I can buy a used transmission for 150. But to fix the old one i still have to drop the transmission

As far as how good the transmission is. I couldn't see any broken teeth or major wear. However the lack of oil made the top end really loose.

 

It might be better to change the tranny if you have wear in the top end . Were is the
Leak at?

 

It looks like the front seal and possibly the top because the sides are just covered in oil

 

If you get a used tranny I'd check the seals and shiftforks before i would put it in
The truck . Also check the rearmain seal behind the flywheel.

 

The shift rail plugs are known to fall out, causing it to leak only when driving.

 

I am probably just going to get a used transmission to stick in it and replace the seals while I'm at it

I'm gonna try and hold off on the forks if I can cause their kind of expensive.

When dealing with those plugs in the back of the shifter assymebly do I need to replace them or can I just use silicon to seal them?

Finally does the transmission need to have the same gear ratio as the rear end or are the transmissions all geared the same?

 

I built up my 1-2 fork with weld. I RTVed my plugs in but most replace them with 5/8 brass plugs. '92-'96 tranny is better than '88-'91. I don't think you'll find anything with different gearing in a 150.

 

the forks are only ~$30 each on Allstategear..com