1994 E150 Van with Winnebago conversion transmission issues

mainelyearth · 05-26-2007, 02:47 PM

Have a 1994 E150 conversion van 5.8 L engine with about 200,000 miles on it. Runs great in the cold or cool weather but when the weather warms up, the transmission starts acting up...usually after we have been driving for awhile or are stuck in traffic. This will be the third summer with problems and it seems to be getting worse. Have flushed the transmission fluid and changed filters regularly for the past three summers ... doesn't fix the problem. The vehicle came with a wimpy auxiliary cooler so my brother added another one ... but the transmission still acts up. As you are driving, it feels like it drops out of gear...sometimes it catches and is okay, sometimes you have to pull over and let it cool off. Have had it in the shop numerous times. Mechanics have taken for short test drives ... so far they have been unable to reproduce the problem ... no codes come up when they put it on the computer and check it. Have had it in to our regular shop and a transmission place.
They keep telling us they can't find anything wrong ... and if we want a new transmission, they will be happy to sell us one.
Suggestions? I have heard the transmission is undersized for this vehicle and if we replace the transmission we should upgrade it. Or at 200,000 miles should we give up and buy a new car?
Thanks for any help .. I got the van from my mom when she died and I am pretty attached to it....
mainelyearth@aol.com

wizzy214 · 06-17-2007, 11:15 PM

try some of that transmissions stop slip, the real thick stuff or the kind that is two different colors then mixes when you put it in.

i had a 78 caddy sedan deville automatic with no reverse and after 3 bottles of that mixes when you poured it in it kinda helped some days it would work....

its worth a shot if not you can go to rebuilding your tranny

mainelyearth · 09-08-2007, 07:00 PM

thanks for the response ...we drained and flushed and put two bottles of transX in it - drove from Maine to VA then to Indiana and back to Maine. It hates the hot weather so we drive at night. Problems will probably disappear through fall and winter...will give us time to figure out what to do .. rebuild or not and who. Thanks again.

E-Rock · 10-23-2007, 05:11 AM

This is a bit late....but have you checked the vacuum line and vacuum modulator on the transmission? Slipping out of gear and then catching again can be a symptom of a bad vacuum modulator. I don't recall if vacuum would be affected by temperature but it would make sense if it did. If you pull the vacuum line on the trans side and see trans fluid, that's a sure side your modulator needs to be replaced. If a mechanic hasn't checked this because they didn't experience problems, it's certainly worth a look before you go rebuilding! Changing the transmission fluid AND filter is a great practice, so keep that up even after you get this problem solved.

Also, are you sure you have enough fluid? I know that may be a stupid question but I know a few people that actually have to over-fill their transmissions a bit in order to eliminate slipping problems.

If you do have to replace the transmission, see if you can find a C6. By far one of the best automatic transmissions Ford has ever made. It's a heavy duty trans and is well-suited for towing.

One other thing I just thought of - are you sure all of the cooling lines are unobstructed? I would definitely install the largest auxiliary cooler that will fit. It never hurts to have it oversized.