5hp24 transmission no reverse

[bdriven]

Hello friends,
yes, still me, with another tranny thread, this time, I do believe I found my problem.....hopefully.....so here's the situation, I did my own rebuild, both tranny, and valve body, put it back together, and the reverse works, but only cold, after it gets hot, or I drive it for about 20 minutes or so, reverse will not engage, so I figured, replaced everything on it, so it has to be the ATF I used.....as I read deeper, realized, that the valvoline I used, differs a lot from what I should've been using (valvoline reads that @40C, 28.1 viscosity, @ 100c, 6.11 viscocity), whereas the recommended for ZF tranny is @40c 38, and @100c, 7.1. now, would you guys think, that this difference, would cause the reverse slipping?
thanks in advance for your thoughts !!

[bdriven]

it's a 4.4i, with 137k miles on it....

[JCL]

Did you use the LT spec fluid, or put Dexron in it?

[bdriven]

Dexron....

[JCL]

Using the wrong fluid can cause shifting problems. You also can't drain it all out, as the torque converter holds 50% of the transmission capacity.

[bdriven]

Thanks JCL, right now I'm in between, dropping the tranny again, or just doing 4-5 flushes, to at least get most of the dexron out....

[jst2878]

Drop the tranny

[bdriven]

...well, I'm dropping the tranny....the question is, if I should look for something else, or solely attribute the tranny problem the wrong ATF.
(slips reverse when hot)....cold no problem....