Ford 4R70/75 Experts, A Moment Of Your Time?

offroadkarter

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So I just picked up a 03 Marauder with a bad transmission. I plan on parting this car out but I'm wondering what could actually be wrong with this thing.

This car has a Precision Industries Stallion torque converter in it with I'd estimate 30-40k miles on it, which is why I'd like to rule out if this is at fault or not.

In drive, the car will rev and slowly work its way up to speed. I took it down the road at the sellers house and if you keep it under 3000rpm the entire time it will just kind of slip through the gears. I had it up to about 45-50mph and the behavior didn't change.

However, if you go above say, 3500rpm, it feels like the torque converter locks and all of a sudden the car takes off. Hard enough that I left two 6ft stripes in my driveway last week.

Now, at this point I would imagine it'd be the torque converter, except for the following:

-Reverse works perfect
-The night I was loading it on the trailer, I'm pretty damn positive reverse and neutral became forward gears temporarily. Since this night the trans has not repeated those actions

Any ideas? Did the converter burn itself out early or is it something with the direct drive clutch? For what it's worth, the fluid is at the correct level and is not burnt/dark, and the PO put a dedicated aux trans cooler on the car.
 

blownstang4.6

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What size stall is in it? Is it a lock up converter? Is it properly tuned to lock up under normal driving/cruising?
 

xblitzkriegx

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That transmission is dead. Yank another trans from a mustang in JY and slap it in.

If you wanted, you could rebuild the valvebody and all the junk in it.
 

offroadkarter

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What size stall is in it? Is it a lock up converter? Is it properly tuned to lock up under normal driving/cruising?

It's a PI Stallion, think its a 3500 stall but I'm not 100% sure. It is indeed a lockup converter. The PO had the car tuned a while ago and I can't imagine he was driving it around like this the entire time.

That transmission is dead. Yank another trans from a mustang in JY and slap it in.

If you wanted, you could rebuild the valvebody and all the junk in it.


Thats the conclusion I came to after doing some more digging, I found someone with a 04 P71 that had the same symptoms with a stock situation, his forward drive drum was shot. This car is getting parted out so I'm just glad the torque converter should be safe.
 

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