Hi, here is my story. Any help you can give would be greatly appreciated.

For starters I have a 1991 f-150 300 cid 2wd 5 speed m5r2

It started off in August when my dad took my truck to pick up a load of bricks. On the way back from the 20 mile trip he reported a funny smell and smoke coming from underneath the truck. Following the transmission made a huge clunking sound and wouldn't put power to the wheels.

After sitting for a while we finally pulled the transmission and took it to a shop. They quoted us 1174.10 for a rebuild. Being the cheap-o's that we are we decided that was outrageous and decided to tackle the beast by ourselves. Needless to say it took us 5 hours to put the bloody thing back together after the shop tore it apart.

After much internet surfing I bought a 4wd m5r2 from a man down in California for 250 bucks. Originally I thought it would be an easy tailhousing swap and it would go right back into the truck. No... the output shafts are completely different sizes. So after dissambly of both transmisssion and reassembly I finally have a frankentransmission composed of the bodies of the former two.

So, we shove it back under the truck, pore some ATF into it, and see how she drives. 1st gear... wow sounds good so far, 2nd gear... wow I think we did it,3rd gear... slight grind hmm thats not good,4th gear... oh god big grind we really f-ed this one up, 5th perfectly smooth.

More internet surfing and we find that Redline MTL has been the miracle cure for everyone elses gear grinds. After much searching I drop 40 bucks for 4 quarts of miracle cure. After swapping fluids, the test drive yields better but not perfect results. After 3 days of driving the truck is back sitting because the grind is as bad as it ever was.

So, thats the story. Everything inside the transmission looked pretty good after swapping the stripped gears. Shift forks were good and the gears still had sharp points. The synchros didn't have a huge amount of wear but I have a feeling they are the culprits. Does anyone else have any ideas of what might be go on? I tested for clutch drag, I tried waiting and letting the synchros slow down but to no avail. The slower I shift the better it is but its never perfect. What do I do? Spend 130 bucks for new synchros from southern gear? Just throw the transmission away and swap a zf? I would really like to get this one working and for as little money as possible.

Any help would be greatly appreciated.

And here, after I had spent countless hours trying to figure out how to put it back together, I find the best and only m5r2 rebuild site on the net. (who knew they put these things in t-birds?)

http://www.fivaxis.com/m5r2rebuild/
http://www.fivaxis.com/set4/
http://www.sccoa.com/forums/showthre...highlight=m5r2

hope that helps anyone doing the same thing I did

 

That's really good information, I'm going to file that away...

 

Anyone else have any advice?

 

Sorry, it sounds like syncros to me. Especially if the Redline helped just a little bit...

Does it go in smooth if it's double clutched like you would a big truck?