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Discussion Starter #1
New build turbo 400 with Hispster t-brake RMVB behind approx. 800hp BBC. Tight 9.5" nitrous converter (approx 3800). Car has been street driven about 20 miles so far. Problem is when the trans gets some heat in it it has a hard time moving in reverse. RPM's have to come up quite a bit to make it move. I am using neutral and t-brake for reverse. Moving forward all three gears shift great with no lag. Also t-brake holds in first gear with no sliping or car movement. Any ideas where to look first? Thanks in advance.
 

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Discussion Starter #2
Just a note....I just checked the shifter cable and it checked out ok. Cranked the car andit went into reverse no problem. Gonna drive it and check it out. Thanks
 

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The ratio is different in reverse , it may take more rpm to back up or there may be a hydraulic problem. A pressure test in all ranges will confirm if there is a problem or not. Do the test at idle and 2000 rpm in all ranges and report back.


Hutch
 

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Discussion Starter #4
Well I made a short drive to family members buisness. Got there same problem with reverse. Checked transbake in low gear and it held no problem. Started the drive home. Got it up to about 60 mph and kinda got in it up to about 90 mph. After I got out of it I could tell it pushed some fluid out the vent and it started slipping. Was close to home but it barely made it in the garage. Get this.....when I got into the garage I tried reverse and it hit pefect like it did the first day. Tried it two or three times and it worked great just nothing in forward. Temp gauge never got over 190 but the sender is in the pan and the fluid smell burnt. Just gonna go ahead and take it out and back to my builder.
 

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Discussion Starter #6
Its coming out tomorrow. I will try and get some pics if I can be there when my trans guy pulls it apart. Thanks again Hutch.
 

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What fluid are you using? Is it overfilled?

You coming to the 11th street cruise this weekend?
 

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Discussion Starter #8
I was using type F and if was about a quart over full. My whole year has been spent trying to make it ready for the cruise. Gonna have to wait till next year.
 

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Im not sure about the 400s, but have you ever heard of using a mixture of ATF and F? I also remember hearing of someone running something much thicker, I think it may have been gear oil but I cant remember. Who built the tranny? Was it Hilton?
 

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Discussion Starter #11
Hutch I won't be making that cruise but it's not a problem. I have come this far with the car so there is no need to rush things and possibly make it worse. Guess patience comes easier with old age.....lol. Ricksters I have heard of some using hyraulic fluid and regular trans fluid to make it thicker especially for the turbo guys who are on the trans brake to build boost.
 

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Discussion Starter #12
Well I got the trans out and to my trans guy. First problem found was one of the sealing rings on the pump came apart. He believes thats what caused the severe slipping in forward gears that came on suddenly there at the end. Second thing found was that the sprag drum actually came in contact with the center support and machined a groves into both. He's not sure that the drum can be used again. He said he's never seen that happen before. Thats as far as we got. He'll finish taking apart the rest tomorrow. I took some pics with my camera phone. Will try and load them when I find my data cable.
 

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Discussion Starter #14 (Edited)
The rings were blue and kinda a soft, pliable material maybe teflon?. Not really sure what they are made of but there were two of them and one came off. Any idea why the drum would contact the center support Hutch?
 

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Pretty odd for a ring to come off. I have seen them get cut going together but they stay in their groove after that. The only way the drum can contact the center support ring lands is if the bushing was badly worn or the intermediate pressure plate came in contact with the drum and knocked it off center causing the wear to take place.

I hope he gets it fixed up properly for you this time.


Hutch
 

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Discussion Starter #16
The sealing ring was cut so it was one long piece and was twisted like maybe it got hot. Also when my trans guy built the trans I bought a billet input shaft and per the instructions it states that the shaft does not have any holes (oiling passages I assume) in the front of the shaft therefore you must remove the front stator tube bushing which in turn requires a converter with a turbine bushing so the input shaft can be supported. I made sure my trans guy knew this and I watched him remove the bushing. From what I seen the contact did not look awful but then again I have never built a trans.
 

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Discussion Starter #18
Hey Hutch, from looking at the clutches and such it seems we caught things before they were really burnt. Would just a general flush of the lines and cooler (external cooler only) be ok? I did not see any metal flakes or shavings in the oil just a slight darkening in color. Also thought about drilling 1/8" pipe plug in the converter like I read in another thread. Any suggestions?
 

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If you don't have a mess I would not worry about flushing the converter , just drain it the best you can and blow out the cooler lines. If you have to flush or drain the converter in the future I would suggest just a small hole and use a 1/16" NPT allen head plug so it won't upset the balance.


Hutch
 
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