Using wrong transmission fluid

37chief

Well-known Member
Location
California
Both of my son in laws are not very mechanically gifted. One of them just drained the fluid in his 08 Ford 150 4X4. Now he is having transmission problems. Will the wrong fluid actually cause transmission problems? Stan
 
Transmissions are not as simple as they used to be. You have to be specific when choosing transmission fluid. I have one vehicle which uses plain transmission fluid. Then another that uses full synthetic. Then we have a dodge truck that calls for synthetic ATF+4.
 
you didn't say why he drained the transmission. was he having problems before or just thought it needed it. most books are explicit about the type of hydr fluid to use in trannys. Nothing wrong with doing it your self even if you don't have a lot of knowledge but you do need a manual to assist you. if it were mine I would drain it back out and make sure I used the right fluid ford calls for. I believe there is also a filter in there that should be changed with the oil.
 
(quoted from post at 22:38:42 12/03/18) Both of my son in laws are not very mechanically gifted. One of them just drained the fluid in his 08 Ford 150 4X4. Now he is having transmission problems. Will the wrong fluid actually cause transmission problems? Stan
ifted or not, my opinion, when it comes to automatics is leave it along if it isn't broken, maybe other than top it off if it might ever need it. Yeah, some will disagree, especially those selling something, but I don't care.
 
The sliding bits are more sensitive to fluid type. Synchro cones in a manual and clutch material in an automatic. Manual trans will work on wrong fluid just be hard to shift / ruin the synchros. Auto trans can get pretty messed up if the fluid lets it slip even a little bit too much.
 
What fluid did he use, it looks like Mercon V is recommended and that fluid has been around since the mid 90's. It's definitely not a new or modern fluid.

Almost every manufacturer has their own fluid spec, there are even OEM's that use the same transmissions as other OEM's and they will have different fluid specs between them. I'm not saying all fluids are the same but most are not very different at all, at least if he used a modern spec fluid. The biggest changes in modern fluid specs was going to a synthetic, or blend for longevity and viscosity , friction modifiers are another change. If he dropped the pan and changed the filter he only changed less than 1/2 of the total fluid out anyway.

So if his concern is shift quality/feel (soft/hard ) or shudder during torque converter engagement, it's possible the fluid is causing that, but with only changing 1/2 the fluid I doubt any harm has taken place because of the fluid. Tell him to change it again to the proper fluid but depending on symptoms, it might have other concerns (maybe the reason he changed it in the first place?)
 

Not the 150, but many cars transmissions are "sealed" there is no dipstick. You can drain some out the drain plug, but only about half, and then you need to pump the replacement fluid back in through the same hole. When this topic came up a year or two ago there seemed to be a general consensus that if you have one of the sealed type, and it is supposed to get the periodic drain and flush and refill, and it doesn't get done as scheduled you are likely to get worse problems when done significantly late.
 
Many a trans. died just right after a fluid change ! Mostly because you did not do them often enough and waited until it was too late.
 
If it is supposed to have Ford Mercon SP fluid, the wrong fluid will cause problems. Auto parts stores will tell you different and sell you what they have in stock. Any Ford dealer will tell you to use ONLY type SP. I changed my fluid in my 2008 Expedition because I had to repair a minor leak. I was told by the dealer to use only SP, or they would be glad to repair or replace the transmission later. He said it has happened many times that people put in the wrong fluid, and then troubles start. By the way, there is no "Equivalent" fluid. USE ONLY TYPE SP if that is what your manual calls for.
 
(quoted from post at 21:38:42 12/03/18) Both of my son in laws are not very mechanically gifted. One of them just drained the fluid in his 08 Ford 150 4X4. Now he is having transmission problems. Will the wrong fluid actually cause transmission problems? Stan

I may be completely wrong here but I have seen it many times when someones transmission starts acting up they decide/hope that changing the fluid or dumping in bottles of magic juice will make their problems go away.

Was it really just fine before he drained it?

Busy time of the year with Christmas around the corner and not the best of weather to be working on a vehicle right now so it seems odd for someone not mechanically inclined to suddenly take interest in a messy maintenance job.

If he told you he was also changing the diff oil and antifreeze as part of his new interest in performing routine maintenance then disregard my comment.

Can the wrong fluid cause problems?
Yes and no would be my answer without knowing what kind of fluid he used it is hard to say.

If he filled it with 80/90 gear oil then a definite yes.

If he replaced non synthetic with a compatible synthetic for example then probably not.

Did he also change the filter?

Not fully seated, wrong filter (deep pan) two seals or no seals tend to be the most common causes of transmission problems developing immediately after a service.
 
Yes it can,, and also if your running a ford with a 5.4 engine anything heavier than 5-20w will junk the Cam Phasers,,for sure...they are hydraulically operated with the engine oil,,thicker oil raises the oil pressure and blows the seals out..Yes we live in a different world now,,and we need to pay attention to things like this...
 
YES.... Case in point. My wife drove a 1976 Mercedes 240D for several years. It was a 4 speed standard transmission. The owners manual called for Dextron something or other automatic transmission fluid. I decided to put Amsoil automatic transmission fluid in it " because I could ". Big mistake, it ground gears on every shift until I switched back. End of problem. Ellis
 
He drained the fluid and is now having problems.
That would be a problem if he is operating it, or trying to, with the fluid drained from it.
Will the wrong fluid cause problems?
Well, bad news is "Air" is not a fluid. Air is good for pneumatic operation. Most automatics prefer hydraulics operation.
Maybe your son is trying to invent a Pneudraulic upgrade?
Sometime in my past I was a "Pnuedrualic" mechanic.
I never hard of it for automotive automatic transmissions though. . . .
 
(quoted from post at 10:58:00 12/04/18) He drained the fluid and is now having problems.
That would be a problem if he is operating it, or trying to, with the fluid drained from it.
Will the wrong fluid cause problems?
Well, bad news is "Air" is not a fluid. Air is good for pneumatic operation. Most automatics prefer hydraulics operation.
Maybe your son is trying to invent a Pneudraulic upgrade?
Sometime in my past I was a "Pnuedrualic" mechanic.
I never hard of it for automotive automatic transmissions though. . . .

Geeez Bruce, pretty numb.
 

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