Dresser Dozer gear shifter pushes itself forward

[Bradlyn Wadel]

I have a Dresser TD8G Dozer that runs very well. I recently replaced one hose from the shifter valve body to the transmission. The next time I used it it worked fine for about 5 minutes and then the gear selector started popping out of gear into neutral. After another five minutes, the gear selector started being pushed back toward and into neutral as soon as I put it in gear. After being in neutral a few seconds, I could pull it into gear and it would go for a few feet, so i took it over to the shed that way. Is anyone familiar with this issue?
I wonder if it could be the seals in the shifter valve are blown out and pressurized oil is getting into the back of the valve and pushing the selector valve forward. Does this sound right? What do you think the problem could be.
Also, does anyone know of a good source for dresser Dozer parts in the southeast?
Thank you, Bradlyn Wadel

 

[StanRUS]

Had issue similar with TD20, shift valve internal leakage causes by wear and transmission valve body wear, i.e. housing to spool excessive clearances. Had to replace both valves to remedy the problem! Dozer with reverse line blocked off (plugged with 1/8" pipe plug) would self shift from 1st gear forward into reverse caused by oil by-passing the shift spool...

 

[tractorman77]

I have a TD8E that also has a shifting problem, maybe you could help. This is what it's doing... When I start up in the morning, the dozer works fine, goes forward and reverse in all gears and everything. If I shut it down for lunch, when I start it back up the darn thing won't go forward or reverse. It seems like it tries to move a little, then stops, regardless of which gear I have it in. Sometimes, I can shift forward and back repeatedly for 15 or 20 minutes and then the gears will begin to work again. Once it begins to move again, there are no problems in forward or reverse. Talked to a couple of guys, one suggested the transmission pump is weak and when the oil gets hot it can't build up pressure. Another disagreed and said that if the pump was weak, it would have a problem all the time. There are no discernible leaks. Yet another guy said that there may be a vacuum problem and check the transmission breather. At this point, I just don't shut it down for lunch and get really hungry at the end of the day. Any ideas?

 

[tractorman77]

Also, as for dozer parts, I've found that FP Smith has a good selection, but they are pretty expensive. Frontier Tractor in Coldspring, Tx has a variety of used parts. Their yard is full of dismantled dressers.

 

[td15c]

Tractorman77 I would guess you have a suction leak or a week charging pump. Does the td8 have a trans pressure gauge

 

[tractorman77]

It has a clutch pressure gauge and it shows that I have good pressure. Is that what you mean?

 

[StanRUS]

It has a clutch pressure gauge and it shows that I have good pressure. Is that what you mean?

Did the problem start suddenly or gradually become worse? Have you checked the trans filter and screen for metallic debris?
From your' description hot oil is leaking by??? guessing...forward-reverse clutch pack seal rings. When you sit and shift back and forth into forward-reverse and the trans starts working normally after 20minutes, to me that indicates oil filling issue with forward-reverse clutch packs. Maybe shift valve issue also. Gauge pressure won't necessarily indicate internal leakage.

 

[td15c]

If you have no clutch or trans pressure when it won't go in any gear it's a good bet that you have a suction leak or a weak charging pump. If you have good pressure then you probably have a contol valve or clutch pack problem.

 

[oarwhat]

Tractorman we had the exact same dozer with the exact same problem. We used to let it idle in gear for lunch. If you forgot it wouldn't move and it gets worse over time. We tried everything pumps ,hoses etc etc. nothing fixed it. I traded it in and a mechanic bought it and he couldn't fix it either. He put in a reman . Sorry I don't have an easy answer.

 

[tractorman77]

Thanks for the feedback Oar, but I'm stuck with this one. The clutch pack problem... I'm guessing that means I have to pull the transmission? I'm trying to avoid that since I just had the torque converter rebuilt. I asked the guy who did the converter if he cleaned the transmission filter and he did.

 

[Iron@Dirt]

Thanks for the feedback Oar, but I'm stuck with this one. The clutch pack problem... I'm guessing that means I have to pull the transmission? I'm trying to avoid that since I just had the torque converter rebuilt. I asked the guy who did the converter if he cleaned the transmission filter and he did.

if it started right after hose replacement try another hose.