A40D transmission heats up then leaks but slow no problem

[women fly]

My 92 1992 Holiday Rambler SASX Imperial Class A on F53 chassis with A40D transmission with overdrive... transmission oil overheated and spewed out. Voluminous smoke which ceased when it cooled off as it was dripping onto exhaust. Drives and shifts fine and no problems at slow speeds up to 35 or 40mph.

However after 10miles or so at 55mph it begins to heat the transmission oil and at 300degrees it spews and smokes.

Anyone have that problem? ONe shop says seals would solve problem but can not deal with big rv. Another doesnt even look but says I need a $3500 exchange transmission.

I wonder if transmission cooler could be clogged ? The temps here were 95+ I have been in hot wx before but never had a problem. I had hauled a little 12ft cargo trailer 800 miles with no issues..in temps as high. Not a bobble.

Any suggestions? Would somewhere like camping world be better than a transmission shop? I have found Ford dealers would not even talk to me about RV..so have not called any of them.

Radiator shop...said they cant test or check transmission cooler...to see if it is clogged.
That too...makes me wonder why not?

I have had no problems with this lovely well kept bus in over 11k miles .. it has 55k miles
No clunks or slaps in drive train..it runs like a dream. Last year a pinhole in heater core..the original..fixed and driven 5k miles no problem. Oil change and put in a K&N air filter 1k miles ago.

I was in reverse backing the trailer..when it happened first. 2nd time as I say driving 55mph and let off gas after cresting 3rd hill.

Let it cool an hour..drove it back the 14miles under 40mph...no leak no smoke no problems.

[women fly]

My 92 1992 Holiday Rambler SASX Imperial Class A on F53 chassis with A40D transmission with overdrive... transmission oil overheated and spewed out. Voluminous smoke which ceased when it cooled off as it was dripping onto exhaust. Drives and shifts fine and no problems at slow speeds up to 35 or 40mph.

However after 10miles or so at 55mph it begins to heat the transmission oil and at 300degrees it spews and smokes.

Anyone have that problem? ONe shop says seals would solve problem but can not deal with big rv. Another doesnt even look but says I need a $3500 exchange transmission.

I wonder if transmission cooler could be clogged ? The temps here were 95+ I have been in hot wx before but never had a problem. I had hauled a little 12ft cargo trailer 800 miles with no issues..in temps as high. Not a bobble.

Any suggestions? Would somewhere like camping world be better than a transmission shop? I have found Ford dealers would not even talk to me about RV..so have not called any of them.

Radiator shop...said they cant test or check transmission cooler...to see if it is clogged.
That too...makes me wonder why not?

I have had no problems with this lovely well kept bus in over 11k miles .. it has 55k miles
No clunks or slaps in drive train..it runs like a dream. Last year a pinhole in heater core..the original..fixed and driven 5k miles no problem. Oil change and put in a K&N air filter 1k miles ago.

I was in reverse backing the trailer..when it happened first. 2nd time as I say driving 55mph and let off gas after cresting 3rd hill.

Let it cool an hour..drove it back the 14miles under 40mph...no leak no smoke no problems.

[AndyG]

I'm no expert on this transmission so we will start with the easy stuff. Do a visual inspection of the trans cooler. Is it clean? Are the fins nice and straight? Is there anything in front of it obstructing airflow? If you need to clean the cooler I do not recommend a pressure washer because the high press water can flatten the fins. If the exterior of the cooler is clean you may have to dig deeper. Write back if this doesn't help and we'll think about the next step.
BTW Pull the trans dipstick and tell me what color the oil is.

["007"]

woman fly welcome to irv2 and the Ford forum.
Looks like Andy has got you started you can try this Link if you need to go further.
Enjoy the forums and do post often.

[TomBr]

The previous owner of my 94 Coachmen had a Jasper rebuilt unit put in. I notice on their web site they comment that they install a supplemental cooler, which I see on mine, with their units. Is your fluid level right? I think 300 degrees is too high-I always heard 270 was about max.

[TomBr]

Actually, some references I found say 170-200 degrees is normal-yours is getting way too hot. You need to check out, or have checked out, your cooler (transmission radiator) and fan.

[DriVer]

I know this one!

One solution to this event would be to install a Banks Trans-Command. You can see it on their website. The TC turns an E4OD from a mush-o-matic into a pretty good gear jammer. Firm shifts translates directly to less slippage which means much reduced opportunity to over heat.

I have used 2 TCs on my past Ford vehicles without having experienced an overheat or fluid loss.

[jrcnlc]

Three things to ck does trans have an inline filter installed looks like big fuel filter in trans cooler lines,magnafine filter.does trans have a cold bypass a line on side of trans between cooler lines,when cold it bypasses cooler till warm the valve sticks in there sometimes.main trans filter dirty remove pan change oil an filter,when oil gets above 240 deg it gets burnt an no good,remove lines an blow out with air

[Hikerdogs]

If the transmission fluid has reached 300* it would only be prudent to lower the pan to check for debris. As was mentioned earlier if the fluid temp exceeds 240* it deteriorates rapidly.

I would bet the leak is from either the seal where the torque converter slides onto the transmission pump shaft or the o-ring that seals the pump to the case. If it's either of these it can be diagnosed without removing the transmission. The downside is the transmission needs to be removed to do the repair.

If they find debris in the pan other than a slight amount of grit from normal clutch wear it's only a matter time before it fails.

I would try either a Ford truck shop or an independent truck shop. If the problem looks serious get an estimate for both rebuilding the current transmission and replacing it with a rebuilt.

Most shops want to go the factory rebuilt route to limit the time they have invested and the possiblity they may have to fix it for free if it returns. A good transmission shop would rather do the work themselves rather than see the money go to a third party.