4R75 no reverse --- times TWO
 

This week I have had 2 transmissions brought to me, both complaining of no reverse.

The first belongs to my nieghbor, its an 2005 F-150 4wd. He says last week it made a loud "POP" noise and reverse stopped working. This is a truck he uses for his work and its got 337K on it. A remanufactured transmission was installed at 70K.

The fluid in this transmission was very dark and dirty. I doubt it had been changed since the reman transmission was installed.

Once I got the transmission apart, I found the reverse band was worn and broken. This is cast band, so it would make a rather loud "POP" when it breaks.


Attachment 7098

The sungear bushing was worn and grooved and scored the snout on the direct drum.

Attachment 7099

Attachment 7100

The Over drive band was burned and pitted.

Attachment 7101

Since this is a remanfactured transmission the case is painted gray, the paint is blistering from heat.
The torque converter has been so hot the paint blistered and the metal was rusting.

Attachment 7102

The sealing rings on the pump stator had cut mild grooves into the reverse drum and the snap ring that holds the intermediate one way clutch on the reverse drum was bent and about to fail.

Attachment 7103

Attachment 7104

Attachment 7105

The over drive servo snap ring was broken, which seems to be common on these trucks. The aftermarket replacement snap ring is hardened to resist breaking and is black in color

Attachment 7106

This transmission will be rebuilt with new gaskets, seals, clutches, both bands and reman torque converter. The overdrive band and low/reverse band will be upgraded with new bands that have a high carbon friction material, that will resist burning. The reverse clutch pack will be improved with 4 clutches, instead the 3 clutches from the factory and I will install a spiral locking ring on the intermediate one way clutch. I am also replacing the direct drum and sun gear



The second transmission that lost reverse is from a 2006 F150 4wd. The owner of this truck removed the transmission himself and brought it to me.
I am told the truck has a lift kit and larger tires.

The residual fluid is clean and bright red. The owner has a drain plug installed in the pan, so I can assume the fluid is changed regularly.

Once I got the transmission part, the only damage I found was a broken reverse band. It appears this band has been broken for a while since 2 of the fingers on the band that would still engage were worn to the metal and and the friction material is burned. The band surface on planetary gear was slightly scored.

Attachment 7107

Attachment 7108

Everything else in the transmission shows very little wear.

This transmission will be rebuilt with new gaskets, seals, clutches, both bands and reman torque converter. The overdrive band and low/reverse band will be upgraded with new bands that have a high carbon friction material, that will resist burning. The reverse clutch pack will be improved with 4 clutches, instead the 3 clutches from the factory and I will install a spiral locking ring on the intermediate one way clutch.

The 2005 Truck came back a few days ago, now with 338,540 miles on it. The owner complained the transmission was shuddering badly in OD.

With the scan tool installed, I went for short 5 mile drive. #5 cylinder mis-fired 254 times.

With the coil and spark plug removed from the cylinder, the metal post on the coil was corroded and the plug was worn.

Attachment 6742

Attachment 6743

I cleaned the metal post, put a dab of di-electric grease and installed a new spring and boot and new motorcraft plug on that cylinder.

mis-fire is gone and truck runs smoothly now.

The ironic part of all this is the truck sat at the local Ford dealer for week and they could find no problem since no codes were set. Since I rebuild the transmission on this truck, the battery was disconnected during the rebuild process. The emissions monitors in the PCM had not all run and cleared yet. Because of that NO mis-fire codes will set in the PCM, but you think a trained tech a Ford dealer would know that.

I wish those pics worked - my truck is having a hard time going into Reverse - I'll print this out when I take to the trans guy.

sorry, my picture hosting changed... didn't realize I used the old hosting on this post.

basically, on both transmissions the reverse band was broken.

I am not sure what you mean by "having a hard time going into Reverse"

The truck would act as if it was in Neutral when selected to R. I'd pump the gas pedal a bit and about 2500rpms R would engage.

Dropped the truck at a shop; rebuild in order - they won't know what the status is until they get it apart.

pictures are updated...

sounds like the reverse clutch has lost pressure and has burned. I would bet the front pump sealing rings have worn grooves into the reverse drum, which caused a pressure loss. If you haven't already... I would highly recommend adding an extra transmission fluid cooler to work in conjunction with the factory cooler

Thank you sir - will for-sure get on that when it gets back; or have the shop go-ahead and install another.

The rebuilt on my buddy's 07 with 10k miles on it does that. Concerned me when I drove his truck a few weeks ago haha.

Thanks for the pics and details! Nice to see and read about.

Can you recommend a good cooler?

Hi there,
Just wondering how much it cost to replace a reverse band?

Typically you would never just replace a reverse band. Also, discussion of pricing is a no no. You can private message the OP to get this input on your question and I'm sure he will be more than happy to discuss it with you.

D