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View Full Version : M5R2 - No 3rd gear - What to expect next?



Tim Groth
08-12-2015, 09:52 AM
Title pretty well sums it up - The '89 rolled 218K miles yesterday. at 217,999 3rd gear disappeared. At first it would go into gear and then kick it out, now its just MIA all together. I have a replacement M5R2 that I can swap in from my parts collection, but my question is what can I expect for the next few weeks or so until I get around to doing the swap.

Thanks.

-Tim

jdsgallops
08-12-2015, 10:09 AM
Lots of stress. I had an 87 IROC that would go into 3rd but didn't always want to come out. Made a very nerve racking drive. Never tore into the trans once I replaced it with a newer WC t-5. But with the limited parts availability of the Tbird spec M5R2 I would try to not drive it any more than possible to keep as much as possible from further damage.

MadMikeyL
08-12-2015, 10:46 AM
The damage is probably relating to the shift fork, possibly bent or broken. I've never had this problem on an M5R2, but I did have it on a couple T45s, and one of them a while after I lost 3rd ended up getting stuck in 4th, so my recommendation until you can get it swapped out is only use 1st, 2nd, and 5th.

Tim Groth
08-12-2015, 12:07 PM
The damage is probably relating to the shift fork, possibly bent or broken. I've never had this problem on an M5R2, but I did have it on a couple T45s, and one of them a while after I lost 3rd ended up getting stuck in 4th, so my recommendation until you can get it swapped out is only use 1st, 2nd, and 5th.

Good to know - all other running gears work at this point. I purchased the car w/ 199K on the clock and the 1-2 and 2-3 shifts have always sounded terrible when engaged. I figured the synchros just finally gave up on third. I've been doing the 2-4 shift without problem since...going on 100 miles or so of this.

I am less concerned about the damage it's doing but more so the stranded on the road. I've also had a shift fork Stick - my 94 SC did that and got stuck in 3rd gear prior to it being rebuilt. But nothing like this...Third Gear is now neutral when driving it's wild.

-Tim

davec73
08-12-2015, 02:38 PM
Yeah if you get no engagement at all I'd say it might be the fork or the linkage in the cover that moves the fork more than likely either way you should be able to tell by pulling the top cover off the tranny.

Mike Puckett
08-13-2015, 10:56 AM
The shift rods in the top cover have been known to break. Usually they leave the tranny stuck in 3rd. Yours may have broken when it came out of gear. The other thing is that it could have broken some teeth off of the gear or the synchro but I think you would have heard some crunching if that happened. I've got a spare top cover if you need one.

Tim Groth
08-14-2015, 12:30 PM
The shift rods in the top cover have been known to break. Usually they leave the tranny stuck in 3rd. Yours may have broken when it came out of gear. The other thing is that it could have broken some teeth off of the gear or the synchro but I think you would have heard some crunching if that happened. I've got a spare top cover if you need one.

I might look into that Mike - I was considering reaching out to you on rebuilding one in the future, since you or DD are the know guys who are good at doing so. Just right now I just have way more important things going in life with the purchase of my new home and a wedding coming up.

As mentioned I have a spare known good M5R2 I can swap out (and will) but at this time it just makes more sense for me to tag one of my other (5) SC's and tinker with the car when it makes more sense.

Also this '89 has several other items that need to be shown some attention. In the last month or so the wipers have went out/Blower motor quit/passenger widow motor needs new gears/a vac leak I can not find but can hear (I've sprayed the engine with carb cleaner near the sound with no change in the engines sound...then this.

-Tim