Reverse issue

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7duster4

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I think something is wrong with my transmission. It's the original 904 but with around 10,000 miles since it was rebuilt. This only happens when its been sitting for a while. I would say at least a week without moving. Yesterday for example I went to drive it. When I shifted into reverse The car instantly shifted and the rpms dropped as normal. When I let off the brake it didn't backup. My garage floor is flat. I let it sit for a few seconds then it started to move. I was thinking I was low on fluid. After a good drive I popped it in neutral to check it and the line was almost down to "add 1 pint" Is my trans about to take a crap? I sure hope its okay being it was rebuilt a few years ago. When driving it shifts fine through all gears. If something is wrong can it be fixed with the trans still in the car?

Any info is greatly appreciated. Thanks
 
Yeah, add a pint of fluid. Sounds crazy that that little bit would make a difference but it does. Reverse requires the most line pressure and low fluid will drop it enough to slip. If you haven't changed the filter and fluid since the rebuild, now would be a good time to do that. The filter may be partially plugged from all the loose crap that comes out after a rebuild.
 
Sounds like the torque converter is draining back when the car is parked. Not a huge problem just a checkvalve not sealing 100%. Try starting the car in neutral when you first start up after the car has been sitting for a while then shift into reverse if it shifts normally then its just drain back.
 
Thanks everyone I really appreciate. I'll probably drive it tomorrow and i'll see what it does when starting in neutral. Of course adding more fluid is something that should and will be done.


Thanks again
 
I think there is more to this, i had same problem, new 100% rebuilt by TA , 904, always felt like locked a little when first backing up, OK later; Ok if warmed up too. Not a fluid level thing.. It was as if reverse band was not releasing; Band is always on by spring, remember, it releases to back up ,and clutches (or sprag?) carry torque. So thinking was, it was left partially on when backing up, but only when cold. I thought it would be OK,wear in, but at 17k it was getting worse. I opened trans .rear band was wrecked pieces in pan, some metal chips in pan too, no adjustment; sending back to TA momentarily...I hope they stand behind it. I put in low first and had to go new converter as it had small input spline (early 67 ) ; big bucks to punt at 17k.

There is some syndrome to this; one good trans mechanic said seal rings in front can leak,or similar, not installed right, not enough pressure to release band,

It also would be hesitant about 2-3 shift when cold, throttle linkage perfect. on a slant six ;

related , new converter has scrape marks where it hit on front pump cover,...weird. opposite of above, too far into bell..

Any comments welcome. No email communication at TA can be pain in ***,but hope they come through..
 
Torque converter drain back is an extremely common problem with all nearly torqueflites. The problem is just as Daliant said. Low fluid doesn't help but it's most likely just draining back when setting. Remember torqueflites open the oil port in park so no fluid flows. That also allows the torque converter to drain back.
 
jgrady said:
I think there is more to this, i had same problem, new 100% rebuilt by TA , 904, always felt like locked a little when first backing up, OK later; Ok if warmed up too. Not a fluid level thing.. It was as if reverse band was not releasing; Band is always on by spring, remember, it releases to back up ,and clutches (or sprag?) carry torque. So thinking was, it was left partially on when backing up, but only when cold. I thought it would be OK,wear in, but at 17k it was getting worse. I opened trans .rear band was wrecked pieces in pan, some metal chips in pan too, no adjustment; sending back to TA momentarily...I hope they stand behind it. I put in low first and had to go new converter as it had small input spline (early 67 ) ; big bucks to punt at 17k.

There is some syndrome to this; one good trans mechanic said seal rings in front can leak,or similar, not installed right, not enough pressure to release band,

It also would be hesitant about 2-3 shift when cold, throttle linkage perfect. on a slant six ;

related , new converter has scrape marks where it hit on front pump cover,...weird. opposite of above, too far into bell..

Any comments welcome. No email communication at TA can be pain in ***,but hope they come through..
Click to expand...

Sorry but the reverse band is not always on by spring pressure. Whoever told you that is wrong. The reverse band is applied in reverse (hence the name "reverse band", it does not release when backing up) and it's applied in manual low to take strain off the sprague. It's applied by hydraulic pressure not the spring. The spring is to release it. Sounds like your trans. had the rear clutch pack set too tight. The rear clutch pack is for forward only. If it's too tight it'll cause binding in reverse. Binding will chew stuff up fast. Not sure on the torque converter issue. Never seen that happen. But it don't sound right and needs investigated.
 
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