Transmission woes

[Dan B]

I apologize if this has been a topic before, but I searched and I did not find a topic about this yet.



Brief history: I have a 07 Sport Trac, 4.0, 2WD, got it with 50K on it 4 years ago. Now I'm over 100K, and I have not done any maintenance to the transmission (5R55S). I do not tow, nor do I abuse my vehicle - that is what my car is for. I have done hours of research on these transmissions and know their issues. But the issue I am having does not seem to match any of the known problems out there...



The issue: Lately I've developed a noticeable bump or thump on upshifts or downshifts-all gears. It will not do it when accelerating steadily or hard but if I'm accelerating and a car slows down in front of me - I let off the gas and it will thump upon shifting up. When coming to a stop I can hear it thump into first when I'm coasting slow. I do not have any issues with OD, no other shifting issues aside from this noise. I do sometimes have a slight hesitation when I'm coasting to a light to take a turn, and when I hit the gas it seems like it hesitates before 1st takes off (TPS maybe?) but does not do this all the time.



I was planning on testing the solenoid pack but I question that effort as if it was the cause - I'd have more than just a thump issue. I am definitely planning on a drain/refill, filter change and band adjustment this weekend. Years ago I did check fluid level and topped it off because I had to change my radiator - was fine after that though. Case bore/piston issue - I'd have loss of gears correct? I don't even know - the bores could have already been fixed prior to my ownership. Some people said "grease the splines" but the only splines I see are the transmission end of the drive shaft and I don't want to contaminate anything in the transmission. I also did disconnected the battery for a while to clear any programmed things.



I have no problem taking the transmission out and rebuilding it if it comes to that - I've done many rebuilds before and lots of mechanical work but this one has got me clueless, and I don't want to spend time & money guessing.



Any suggestions? Would a shift kit help/? Anyone experience this before? Thanks in advance for any help.

 

[Vic Sorlie]

I'd do a fluid service then get the TCM reflashed (dealership) to latest Ford program, then evaluate. Do in steps if you like, fluid change first.

 

[Yardsale]

Maybe evaluate before spending money on speculation.

 

[Vic Sorlie]

I really think you've got worn-out fluid, probably low level too. No standard dipstick here - it's built into a plug on psgr side of transmission, conveniently located near exhaust tube. With 100K on it I'm dropping the pan to change filter, then full flush with new fluid. That (and a TCM reflash at dealer) is end of road for my skillset. I'm certainly not removing a transmission or tinkering with the innards.

 

[Yardsale]

... and I don't want to spend time & money guessing.

I agree - shop services are expensive; I certainly would not waltz in to a shop requesting services without knowing what is the problem. I might pay for a diagnosis (typically an hour of labor) and make the decision on whether it is something I can or want to handle based on that. Often that diagnosis labor cost is applied to the repair, should the decision be to have the shop perform the repair.



Updating the TCM software might make some sort of difference, but there is no evidence of a problem. Software is not a wear item. If the transmission is in good mechanical condition, a software update should not be needed.



A filter change and fluid flush is not going to magically fix the problem (whatever is the problem). If the problem is simply low fluid, merely filling it will provide a far less expensive indication. If the problem is not low fluid, one can move on and focus resources on further diagnosis. A flush can be performed any time and, if it hasn't been done, I would do it after having fixed the problem.



It seems that this has a sudden onset. I would be looking for something that could change rapidly (torque converter, solenoid, pump, gasket, TPS, etc.). Could be electrical or an electronic component; these can be diagnosed, too.

 

[Vic Sorlie]

dn010, let us know how your work this weekend goes, especially the "band adjustment" which I've never heard of for a modern transmission. Lots of YouTube videos out there - one below may be of interest.

 

[Dan B]

Thank you all, kindly, for all your responses to my problem. Here is a follow-up of the results:



I decided to go the drain/filter replacement route first. I had a chance to drain the fluid, drop the pan and replace the filter the other day. The fluid was dark as expected, the magnet on the bottom of the pan had a lot of black particles attached to it - which I expected since I have over 100K on the transmission and I am not sure if it has EVER been serviced. The filter that was in there to begin with didn't have any specific part number or stamp indicating who it was made by - I'm not sure if these came with Motorcraft or FOMOCO filters but if they did then obviously it was changed at one point. Also, no brass flakes in the pan.



I cleaned the pan out, cleaned gasket surface on the transmission, installed the new filter, installed the pan and filled it up using the pump method through the "dip stick" portion of the plug. I ran the transmission in all gears, made sure the level was correct at the correct temperature. Took it for a drive - came back, drained & refilled a second time and again made sure level correct, cycled through all gears.



At this point, I did not do a band adjustment yet. I am reading conflicting statements where the adjustment is supposed to be 120ft lbs in, 2 turns out, and then a "Ford Updated" statement where it was 120ft lbs, 1 1/2 turns out. I need to research that a little more before I do the bands to see which is the correct one IF I even end up doing them.



Test drive - the banging/bumping/clunking shifting is all gone. I tested this at higher speeds, lower speeds - basically tried everything to re-create a condition where I knew my transmission would bump. No noise now, and in fact, shifting feels much more "crisp".



To the above poster, Yardsale, regarding sudden onset - it could have been these issues but after reasearching them: I was assuming it was not anything major such as TC or pump because I did not have any fault codes stored. I assumed it was not the bore wear issue because I did not lose any gears or exhibit the common problems one might encounter with the bore wear. Last thing I thought it could be and the same as you mentioned, was the solenoid pack; but I took a chance on that agan by researching the problems they'd exhibit when bad and I felt mine was still likely good although I was prepared to test it to make sure.



I am not sure I'm going to mess with the bands - they are simple enought to adjust, I've adjusted plenty of bands on Ford transmissions, especially the C4's in old Mustangs so I'm no stranger to that or even rebuilds. BUT I'm not sure it would exactly be necessary to adjust at this point.



I am satisfied with the results, and hope it will be enough to let my transmission last a while longer. In the mean time, I think I'll shop for a used transmission that I can rebuild so when the time comes I'll be ready.



Again, thank you all for your help and support, ideas and links to resources. I appreciate all the help, and I'm now able to continue enjoying my truck with one less noise, one less worry!



Thanks again - Dan B.

 

[Vic Sorlie]

Dan, thanks for the update. I really though worn-out fluid was your problem. If you want the best fluids for your Trac, check out AMSOIL's online lookup found on my website.

 

[Dan B]

You called it - worn out fluid it was. It has been a week now and it still shifts smooth, everything seems to be in order. I will check out the AMSOIL link you posted above - I want to keep my trac going as long as possible. Thank you again! - Dan

 

[Yardsale]

Curious - did you check the fluid level before starting work?

 

[Jackson Ellis]

Or measure how much came out?

 

[Dan B]

I had checked the level twice prior to draining. The first time I checked it was after coming home from work the day prior to the fluid change. The second was the day of the fluid change again. Once the "dipstick" plug was removed, only a slight drip came down.



I did not measure how much came out, but about 6qts went in each time (changed fluid twice in a row to get higher than 50% change).