another transmission problem?

[Fridge]

I allways read the old posts first but I did not see anything about this. I replaced the tcu on my 91 with a 94 model for the first gear start. I also installed a b&m cooler a while back. If I nail into it and let the car shift itself it would hang for a while at 7k and finaly slip in to gear. I did not notice this before I changed the tcu.I changed about a gallon of fluid and replaced the filter (needed badly) also put in some lucus treatment. The trans shifts much firmer but will rev to the chip unless you pull your foot off of the gas a bit. Could it be the new tcu? I would hate to go back to the old one.

[Q45tech]

The 94's [vs 90-93] different first and 2nd gear ratios cause this as the tcu works from speed rather than rpm*...................why we always recommend a 93 TCU only to change to 1st gear start.

* Actually it is a combonation of worn slower than new shifting and the 5% difference in speed from gearing.

It should shift ok at 137 mph since 3rd & 4th gear are identical 90-96.

[maxnix]

If you had a gunked out internal filter screen, why did you only change out a gallon and leave a gallon and a half of worn out contaminated fluid in the transmission?

That's certainly a contributing factor to your problem.
Modified by maxnix at 3:43 PM 7/27/2007

[Q45denver]

TCU's are pretty easy to swap out and that would tell you if that was the problem. A good flush with BG would also be warranted.

[Fridge]

Thanks Q that answers the question of the shift problem. I plan on changing the fluid a couple more times to get most of the old stuff out. I was not sure how to completly empty the fluid that is why I only changed a gallon . Is there a plug in the convertor?

[Q45tech]

No drain plug, use a BG or other AT pump driven exchange system or just do enough pan drains since you've already cleaned pan and filter.

The 1st drain dilutes the junk by 40% the second by 64% the 3rd by 70% eventually after 5 drains you equal a BG machine ........ use 20 vs 14 quarts however.

[qship96]

The 1st drain dilutes the junk by 40% the second by 64% the 3rd by 70% eventually after 5 drains you equal a BG machine ........ use 20 vs 14 quarts however.[/QUOTE]

Hello,BRIAN,are you there? read the above from the master himself and commit to memory!!!!!!!!!!!!!! I`m quite sure I will be referring you back to this post ad- nausium in our friendly on-going transmission fluid exchange methods difference of opinions!!!

[maxnix]

The main thing that some less than mentally capable persons don't understand is that there is only gravitational flow when drain, not a continuous pressure as when mechanically changed.

It's just llike draining the bathtub after you poop in it when you bathe, Qhip96. The chunks of poop remain in the tub if you don't wash them down with pressure from the shower head.

That's as simple as I can make it for the terminally learning challenged.

Never, not even once, has Q45tech substituted a multiple gravity drain for a mechanical flush in his maintenance regime. He is only saying it is better than never changing the fluid. Real simiple for the room temperature and above IQ.

If you have'nt read all the posts. you cannot simply impose your own delusions as factual.

[qship96]

Brian,after reading the masters words and still not grasping how doing multiple drain/fills is equivelent of a machine flush,you still hang on to YOUR misbeliefs.

if incompetance were incontenance,your pants would be soaking wet right about now!!!!

[Q45tech]

Don't confuse the process of fast 95% ATF exchange with the benefits of a recirculating solvent [BG Quick Clean for transmissions] for 15 minutes in a hot transmission. TWO VERY DIFFERENT PARTS of what some call the same process.

BRAND New ATF [of any brand] WON'T remove varnish or degraded clutch materials like a solvent flush.

As long as the white paper towel test shows the end result [perfect color saturation match] with new ATF, whether one changes by draining and filling , mixing ,draining and filling, etc,etc for a half dozen times or a machine is not significant.

The problem is how do you get 95% of the solvent out while it is hot and has the varnish disolved in it or before it cause other damage by prolonged exposure to what's left of the frictions and seals.

[qship96]

Qtech,I agree 100% -if you are interested in using a solvent the machine process expedites the removal of the solvent as compared to doing multiple drains. I have never used a solvent,just performed annual machine exchanges using synthetic,then switched to annual multiple {5-6}drain/fills timed at 2.0000 minutes again using synthetic atf. So far approaching 200,000 my transmission operates fine,time will tell if it lasts til 250,000-275,000 when the car will be retired