so I blew reverse again.

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timopar

timopar

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Hey Guys, my thoughts are iv got a valve body or shifter problem, or im assembling the tranz incorrectly.
I pulled the tranz out a month ago and found it had pulled the friction material off the rev/low band and scored the drum badly.
I replaced the drum and got a TCI band from summit, I put it all back together, rechecked end float and put it in the car.
I went for a little test drive(5miles or so) after filling it with ATF,
I stopped at a shop for 5mins and on attemping to reverse out of my park, I found rev was slipping.
by the time I got half a car length out of the space it wouldn't move below 2000rpm so I stopped and checked the fluid, fluid was full.
I pushed it out and drove it home, by the time I got home rev is gone entirely.
I noticed a light drag in the car as if I had the brake on slightly and now that rev stopped working the drag is gone.
can anyone help here? anyone seen or heard of this before?
the first time I built the tranz the low band was second hand but this one is new! what the???
 
I would like to know too. Sounds like the same problem I had with mine, I am about to rebuild mine. One day went out and noticed no reverse and the motor felt like something was lugging it down. pulled it apart and found the clutches fried.
 
Anyone bother checking the servo? Was the band just replaced and not adjusted?
These are the questions....
 
Are you doing any racing? If so are you doing your burn outs in second? sounds like a sprag problem. if you burn out in first it tears up the sprag and then the case but feels exactly like the brakes are dragging. Learned this first hand.
 
Ya no, id love to do some racing, that's what I built the car for.
But my car wont pass scrutineering without reverse. :angry7:
My theory at the moment is that the valve body wasn't modified properly,
or its the wrong year model for my case.
Its a factory Chrysler valve body that I purchased from a man who Modifies them himself.
He modifies them as per a DC tech bulletin from the early 70's.
 
the servo's were pressure tested, and the sprag looked great when I had it apart.
the rollers all looked smooth with no marks at all and the springs all very uniform, none collapsed.
I think it must be the valve body, it was converted to rev pattern full manual shift.
ill keep researching and see what I can find 8)
 
As long as the rear band was adjusted properly and you tested the servo upon rebuilding it and it worked properly it pretty much has to be a valve body problem. Something in the valve body is applying the rear band while in drive.
 
If you have a second valve body ,try it.
If it still happens then pull the transmission and find out whats wrong.
I had a cheetah valve body that was not working in reverse.
I had to rev the motor very high to move the car in reverse.
It also shifted very easy \\\ too easy
First to second and to third where so soft you could hardly feel the shifts.
I put the stock valve body back in and the transmission worked perfect.
It is the brain of the trans.
If you took the valve body apart, it might be put together wrong.
 
well I spoke with the man who built my valve body and he tolled me sometimes he has trouble with 727's and the way to fix em is to install a restrictor in the feed orifice to the front band.
I researched this mod and Im sceptical this will fix my problem, I think a new VB is what i need cos it shifts very very softly as it is, even with a blocker rod in the accumulator and a 5.0 kickdown lever.
Could anyone recomend a VB for me please? mancini have thisone http://chucker54.stores.yahoo.net/manvalbodtor.html anyone used one before? will it need the the front band orifice restrictor?
http://cgi.ebay.com/ebaymotors/TCI-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
this one from tci cant be used with my 5.0 lever, I dont realy want to have to change to much more in the tranz ya no. its bin in and out of the car and pull apart and back together a few times now :disgust:
 
timopar said:
well I spoke with the man who built my valve body and he tolled me sometimes he has trouble with 727's and the way to fix em is to install a restrictor in the feed orifice to the front band.
I researched this mod and Im sceptical this will fix my problem, I think a new VB is what i need cos it shifts very very softly as it is, even with a blocker rod in the accumulator and a 5.0 kickdown lever.
Could anyone recomend a VB for me please? mancini have thisone http://chucker54.stores.yahoo.net/manvalbodtor.html anyone used one before? will it need the the front band orifice restrictor?
http://cgi.ebay.com/ebaymotors/TCI-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
this one from tci cant be used with my 5.0 lever, I dont realy want to have to change to much more in the tranz ya no. its bin in and out of the car and pull apart and back together a few times now :disgust:
Click to expand...

A restrictor to the front band??? Never heard anyone having to do that because the rear band is applied in drive. There have been cases where a shim is used to replace the rear servo inner spring to eliminate 1st to 2nd gear overlap but that doesn't sound like the problem unless the overlap is very severe. I have had to use a restrictor to the front clutch pack cause it can come on too fast before the front band releases and cause overlap going into 3rd gear but there's absolutely no reason I know of to restrict the front band. In fact a restrictor would probably make 2nd to 3rd gear overlap worse cause it wouldn't allow the front band to un-apply as fast. Sounds like you need a new valve body and a new trans mechanic.

I don't think the Mancini Cheetah valve body you show there has low band apply so I would NEVER use it on the street because it puts a lot of strain on an already overworked sprague. That's why it says "Not For Street Use". The Cheetah Pro-street valve body part #17675 or 17676 depending if you want forward or reverse pattern. Both costs more but have low band apply. Only problem with most manual VB's is they rarely allow you to use the 5.0 lever. At least none I've seen lately do. Most prefer the 3.8 lever although some will allow a 4.2 lever. Changing the lever isn't really hard to do. When your already swapping the valve body you just have to pull the starter and access cover and you can get a long 1/4 drive extension in to remove the plug holding in the front band lever pin to unscrew the plug and and back the pin out enough to swap the lever. Then re-seal the plug and install things. Takes about 30-45 minutes extra.
 
Ha ha ha thanks Fishy, my mistake, the restrictor is for the front clutch yes, not the band.
Iv got the 3.8 lever that came out of it in the first place, ill just put it back in.
I spoke to a mate who is running a tci and its not low band apply so im avoiding tci.
Iv looked at hughes, A'n'A and turbo action all around the $300 mark,
but griner offer one for $250.http://chucker54.stores.yahoo.net/g.html anyone used one before??
Money talks but I want good VB as well.
 
timopar said:
Ha ha ha thanks Fishy, my mistake, the restrictor is for the front clutch yes, not the band.
Iv got the 3.8 lever that came out of it in the first place, ill just put it back in.
I spoke to a mate who is running a tci and its not low band apply so im avoiding tci.
Iv looked at hughes, A'n'A and turbo action all around the $300 mark,
but griner offer one for $250.http://chucker54.stores.yahoo.net/g.html anyone used one before??
Money talks but I want good VB as well.
Click to expand...

LOL! No problem TI.

I haven't used any Griner product but have heard they are great every time I've read about them so I wouldn't hesitate using one.
 
thats great news, thank u all for your imput.
Oh and my local drag strip is holding a Mopar only race day this saturday,
If I get some good pics Ill post em up in the general section.
thanks Tim
 
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