What do you think it is?(700r4 question)

msheller

msheller

New member
Spent $3300 on built tranny/ 2800 stall from Pro Trans in State College, PA last year. They seem to be a quality outfit.

Ran fine for a year. Dragstrip for 3rd time this past wed nite. 4 passes(12.4's/1.7 60fts) ...on the 4th I foot braked it hard (5-7 psi) felt a small shudder or 2, launched it, spanked a GTO and then pulled into the turnaround...and the tranny wouldnt shift to 2nd w/ part throttle....so I revved it out at part throttle and it shifted(hard!) to the next gear only after revving it way out... rollbacked it home(goodto have friends w/ these BTW) ... drove it 1/2 mile home... seemed to shift into all gears but not without revving it all the way out and or using wot.

Called pro trans...they said one of 3 causes- 1 tv cable ffrayed/broke, 2 governor twisted off, 3 valve body issue... Bob (pro trans)thinks its most likely the governor.

So far-checked the tv cable and seems fine...did not pull the governor yet.

What do you guys think it is?

Thanks,

Matt
 
msheller

msheller

New member
Re: What do you think it is?

Re: What do you think it is?

JS Manufacturing said:
sprag
Click to expand...
They put a new low/reverse sprag in it last year....does that change your guess??

Matt
 
George Blake

George Blake

DONATING MEMBER
Re: What do you think it is?(700r4 question)

Hard bang 1-2 shift can also damage the band but if it's revving high on all of them, it's a valve/pressure issue. You keep banging it and it's gonna be a hard parts issue very quickly. 700s do not like to shift hard.
Forward sprag will act like this:
If you put it in D, it will go forward. If you put it in OD, just revs.
Busted overrun clutch hub will do some weird things to but can be similar.
 
msheller

msheller

New member
Re: What do you think it is?(700r4 question)

George Blake said:
Hard bang 1-2 shift can also damage the band but if it's revving high on all of them, it's a valve/pressure issue. You keep banging it and it's gonna be a hard parts issue very quickly. 700s do not like to shift hard.
Forward sprag will act like this:
If you put it in D, it will go forward. If you put it in OD, just revs.
Busted overrun clutch hub will do some weird things to but can be similar.
Click to expand...

I think I still have all my gears...it just wont shift until hi rpm's in each gear. it also is now louder and harder when i position the stick from park to drive (or od)

Matt
 
George Blake

George Blake

DONATING MEMBER
Re: What do you think it is?(700r4 question)

Your pressure is way up. You need to get it fixed before you break a hard part.
Remove the valvebody and governor, completely disassemble and clean it out with carb cleaner and put back just the way it was. Make sure all the valves move freely and all the springs are put back. It'll shift like new. You need to put a filter on the return line coming off the cooler so you don't keep getting junk in the trans.
 
msheller

msheller

New member
Re: What do you think it is?(700r4 question)

George Blake said:
Your pressure is way up. You need to get it fixed before you break a hard part.
Remove the valvebody and governor, completely disassemble and clean it out with carb cleaner and put back just the way it was. Make sure all the valves move freely and all the springs are put back. It'll shift like new. You need to put a filter on the return line coming off the cooler so you don't keep getting junk in the trans.
Click to expand...


FYI: I have a good tranny inline filter on that return cooler line and its only been there a year. Does that effect your diagnosis? It all started right after a very hard foot brake laucnh at the strip. No probs before. 1 year of troublefree driving on the carefully rebuilt tranny

Matt
 
msheller

msheller

New member
Re: What do you think it is?(700r4 question)

Re: Ask your questions here

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Here's an update on our tranny symptoms(What do u think it is?)

-When moving the shift lever from park to revererse or d it seems to engage into gear alot harder than b4(line pressure too hi?)

-The trannny will shift to subsequent gears but only at a high rpm ...Or in other words, at part throttle it refuses to shift unless revved out.

Keeping in miund that this problem came up after a hard long foot brake launch at the local dragstrip.

What do think?

So far we checked the fluid and the tv cable to no avail. Plan to change the inline filter and pull the gov cover to check the gov....If we can't figure it out after that, then I give up and haul it to the pros.

matt
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