First M5R1 Rebuild Problems | Ford Explorer Forums - Serious Explorations

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First M5R1 Rebuild Problems


March 7, 2015
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Year, Model & Trim Level
91 4.0 4x4

So I'm rebulding the M5R1 from my 1991 4.0 Explorer. My rebuild was looking good up until I started putting the output shaft together. I found the needle bearing in 2nd gear was totally trashed. The gear looks like this:



And this is the old bearing:


I got a new needle bearing, but the gear won't slide on it:


However it fits on there just fine with the old trashed bearing:


Is this gear messed up? The bearing wasn't the main problem I was having with the transmission so I'm thinking about just putting that old bearing back im there and see how long it lasts.

I'm getting the new parts from a rebuilt M5R1 off a 2.9 Ranger. I tried just using all of the Ranger gears and countershaft in my case but when I tighten down the bearing retainers the whole shaft locks up and won't turn until I loosen the front retainer.

I don't have a lot of money to work with here, anyone have suggestions for me?



No more problems here :thumbsup:

I ended up getting a used gear from midwest transmission for 55 bucks. Never figured out why it wouldn't work with that other set of gears but now it has most of the original parts back in it. It's all tight and working smooth as a whistle. I used all the needle bearings, keys/springs, and the synchros from the other tranny so it was well worth the money.

In the end this has cost me about $160 with the new fluid, RTV and cleaner I bought. The local tranny shop wanted $850 just for labor, hah! In all it took me about 2 hours to rebuild this thing with a few hiccups along the way and now press or bearing puller. How can they say it's 6+ hours of labor?

Anyway, it's all back together now and the RTV on the extension housing is curing. Didn't get any pics of the rebuild, I just wanted to get it done. Should have her back up and running this time tomorrow! :salute:

Well of course I had to jinx it. Got everything back in there and went to try the clutch... master cylinder starts spraying fluid everywhere. Getting a new one in today -_-