Tranny Problems - 4R70W

rookie94sc

Registered User
A while back I put in a remfr'd tranny from ford in my 94 SC... I was under the impression that one should use Mercon V tranny fluid in the 4R70W instead of the normal Mercon due to better heat handling properties and such... So when I put the tranny in I drained all the fluid that came with it... Put on a 96/97 deep sump pan and filter and put in Mercon V instead of normal Mercon... Now after 15k my tranny's slipping and I get a whine I believe from the transmission... Is this due to the fluid or did something else most likely go wrong? I bought the tranny just after the switch to the 3yr/36,000 mile warranty kicked in so I have that warranty on the tranny... but I don't wanna take it in until I have an idea what's wrong so I don't get screwed over by ford...
 
The Merc V didn't cause it. When you put on the deeper pan did you install anything to lower the filter pickup? If the pickup point is at the top of a deep pan you can't run low, not even a pint.

Vernon
 
Yeah I put in the filter from the 96/97 tranny that goes along with the pan... So that's covered :) doesn't help to have a deep well pan without the filter to go with it ;)...

Any idea what could've caused it? The tranny was slipping a little while ago and I added fluid right away and have checked it every day since then and it hasn't lost any fluid... The fluid is a brownish color though but I don't see how it could've burned from just that little amount... I've raced it a little but not enought to burn out the tranny in only 15,000 miles...
 
Is the convertor locking up correctly? A nonlocking convertor will make the fluid hotter and could fry it rather quickly if an additional cooler hasn't been added.
 
if you replaced a failed transmission, you need to replace the radiator. If you don't, there's an inline filter that must go on. If you don't do either, you will have a repeat failure pretty quickly.


Also some reman 4R70W's have teflon pump stator support seals which are crap, but it wouldn't casue slippage.


good luck with it. I have the rebuild files if you want to tackle it, it's pretty easy to rebuild.


Brian
 
93 Mark VIII said:
if you replaced a failed transmission, you need to replace the radiator. If you don't, there's an inline filter that must go on. If you don't do either, you will have a repeat failure pretty quickly.


Also some reman 4R70W's have teflon pump stator support seals which are crap, but it wouldn't casue slippage.


good luck with it. I have the rebuild files if you want to tackle it, it's pretty easy to rebuild.


Brian

If I get a tranny cooler with a fan can I just bypass the radiator all together?


Also do I have to have a dealership do the repairs or can any tranny shop do it?
 
I just reread it, so you do have a warranty? If you have some time left, just keep driving it. If it's slipping now, it will get worse with a little time, and eventually need a full rebuild. I'd wait till that happens so they just replace the transmission instead of trying to go in and fix it.

I'd add an inline cooler, but keep the radiator trans cooler. Look at this thread for the filter info.

http://mtcforum.zeroforum.com/zerothread?id=1247

Brian
 
The problem I get is I have this really high pitch whine that sounds like an electric motor matching rpms not supercharger whine... I can't hear it in the engine bay but I can hear it from underneath when revving it so I assume it's coming from the tranny... ideas?
 
Quick question..if you put in an external filter can the one in the pan be removed? Or would a pickup be need to be made?
 
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