Manager Forum

Serviced transmission with machine. Customer picked up and after driving about 8 miles, stopped at stop sign. When they took off, acted like it was in neutral, then when shifted slipped going into 4th gear and OD light was flashing. No codes in computer. Double checked fluid level, all okay. Changed fluid and filter again. Doesn't shift into neutral, but shifts very hard up and down. Any thoughts would be great!!

how many miles on the transmission? i've had transmissions that have never been serviced tank when the fluid and filter was changed.

Steve, I had a couple of problems like that years ago but I haven't had it on anything after the mid 90's. Have you seen any since then? I was kinda hoping that issue had gone away.

that issue is alive and well. the filter isn't sucking air is it? i've had a i've had to overfill a few fords.

114,000

I agree with Steve, I have seen trans quit working after a flush/filter. I have a disclaimer on my flushes that say I am not liable for anything that may occur after flushing. I also note the condition of the fluid on the work order, expecially if it is really bad!

Ive never had a trans quit after flushing not one ever. I agree if the fluid is that bad then there whould be a warning of trans problems that a flush will not cure. If fluid is that bad or problems with shift patterns etc then a flush is wasted money imo. Now not all trans flushes are the same either. Bg machine does not use any outside force to flush no pump or air pressure. this may play a roll in that.

Was the vehicle having any issues before the trans flush. people will ignore the recomended 30k flush or what ever it may be in miles. and they think the flush is like a magic mushroom and will fix it. did customer request flush?

"Ive never had a trans quit after flushing not one ever."

i was able to say that at one time. this van had only 80k on it. never thought it was even close to tanking. drove it in, put it up, changed filter, dropped it down and filled it, put it in reverse and got nothing. got the primary engaging but that was it. revved the crap out of it and it just tried to move. customer went nuts. ended up installing transmission with no labor charge. i was lucky, a chevrolet van, took all of two hours.
when customers come in for scheduled service i will tell them that there is an outside chance of issues at the high mileage services. i tell them of the chevrolet van.
on the flip side i've had transmission pans that had piles of filings and 10lb filters. serviced them and they ran like new. no way to really tell so it's best to cover all the bases.

Any time I see shimmery fluid I warn the customer that it may not help it has metal in the fluid. I also road test good before any trans service. If I found tons of debris in the pan damn sure the custoemr would get a call and told that its on the outs. Do anyones flush machines use outside air or an electric pump?

My flush machine uses only the vehicle tranmission pump during the flush. It has a pump just for filling the machine. If you use a power flusher, I have heard of that possibly causing damage to seals and other stuff inside the trans.

agreed, a pressure flush can and will cause issues. even when i pressure bleed a brake system i use the lowest pressure possible. there can be a somewhat solidified crapolla that is causing no harm where it is but when introduced back into the main stream will grenade the system. it's definitely a pressure issue here and i bet if you took this transmission apart somewhere you'll find a seal, valve, or solenoid stuck. the unfortunate thing here is there is a pretty good chance that even if you find and repair the issue when the transmission finally fails the service you did will somehow contribute to it.

I assume the correct fluid was used, sometimes it's the silly questions.

no such thing as a silly question. sometimes only silly answers.

steven kiser wrote:no such thing as a silly question. sometimes only silly answers.

so true

HAve had several of these go bad after a fluid change. Wipes the clutches out for some reason. Last one was very recent, Fleet F250 was in for a PM, Brakes,leaf springs LOF and trans service. I test drove after repairs and they came and picked it up. made it 2.5 miles and quit. But then the guy that drives it all the time says to me, " Oh, the trans has been acting up for a few weeks now." I would suspect the customer may have had an issue and like someone said, figured a flush and fill would fix it. Like the infamous "I think I need a tune up".

On these Fords I keep as many of the trans speed sensors in stock as I can,( Input and output) you may have loosened up enough dust to collect on the magnetic sensors to cause it to quit reading. The harsh shifting would be a sign of this.

We also use " cooler clean" to flush the cooler and lines prior to flushing the rest of the system.