Crap, th350 emergency

[Mark Yacavone]

Originally Posted by Mark Ugrich

In addition to the above , if it has a modulator check to make sure the valve isn’t stuck, Recheck to make sure the transmission linkage or cable is shifting fully into reverse.a pressure check will tell you a lot if you can do one.Its straining my memory, but i believe a stuck band can cause slipping in reverse too. Loose filter is a possible too.

No band in a th350, except for intermediate braking.. Should be long gone in a race trans.

[Mark Ugrich]

Originally Posted by Mark Yacavone

No band in a th350, except for intermediate braking.. Should be long gone in a race trans.

If it’s there, the band is manual 2nd. correct?

[Mark Yacavone]

Originally Posted by Mark Ugrich

If it’s there, the band is manual 2nd. correct?

No. 2nd gear clutches are attached the case ,behind the front pump. No band necessary for forward motion.
400s work similarly for 2nd. They do have a band for lo/rev , rather than clutches though.

[Henrys Toy]

Originally Posted by Mark Yacavone

No. 2nd gear clutches are attached the case ,behind the front pump. No band necessary for forward motion.
400s work similarly for 2nd. They do have a band for lo/rev , rather than clutches though.

Good morning to all,
When I first read the post I thought that a lip seal might be the cause, but since it had reverse before, Marks comment on the frictions is probably pretty close to the source of the problem. The TH250 has a" Band Apply" for second gear as does the THM200. I would drop the pan and inspect for friction material and anything metallic. If there is a lot of debris in the pan, I'm not an advocate of running all that junk through the trans and possibly jamming up a valve in the valve body or ruining the rest of the frictions in the trans. This is why a good many racers have Spare transmissions with them. Take a look and go from there. Good luck on your Quest.

Respectfully,
Henry Kunz 1534 H/SA

P.S. Check with other racers and see if someone local can help look at the trans. G.M. built those transmissions by the thousands - meaning there's stuff around that might be able to get you through the weekend.

[Kevin Panzino]

Originally Posted by Mark Ugrich

If it’s there, the band is manual 2nd. correct?

The band is only used used “2” shifter position on a factory trans/valve body to allow compression braking in that gear/position. No other purpose. Class race trans should have it removed.

Kp

[Rob Petrie E395]

Don’t know if it’s your problem. But with my TH350 and PPP shifter. If the cable is not adjusted exactly right. I get no reverse. Even if it’s off a tiny little bit. Probably not your problem. But it’s easy and quick to check.

[Roy Kinslow]

Since it's an emergency as a last resort.... I knew a person with an old ford that would lose reverse , they always carried a bottle of Lucas Transmission Fix. Put some of that in and would be ok for a while . Maybe it raised the pressure and viscosity a bit, I don't know but they swore by the stuff.

[1320racer]

....

[Jim Cimarolli]

I have seen this happen a few times. Most people only put one or two reverse frictions in a footbrake transmission like yours. When you tear it down I think you will find the reverse clutches welded to the plates and all the lugs knocked off the clutches. We all know a person is not going to burn up reverse backing out of a pit area. However, if you often shift it into neutral after the run and your shifter is a bit out of adjustment that's how this happens.