Jamieat

My buddy has an 04 Lariat 5.4 4x4 with the 4R75E transmission.

He was backing up his driveway when....BANG.....faults into neutral, and that was the last of his reverse.

He'd had an issue with the linkage connection once before so, I got under it a few weeks ago (he's been driving w/no reverse for a month) and checked the linkage position and verified all was good there. He does NOT have a CEL on but I've asked him to go by the parts store and have it read to see if anything has been logged that might help us figure out the problem.

Sounds to me like the reverse servo retaining ring could have broken. If this is the case, is it accurate that the reverse servo is much more difficult to access than the OD? I'm familiar with the OD issues of the same problem but this is the first for me with the reverse going out.

When checking the linkage connection, I had him shifting gears while the engine was running. I noticed that if he in park, the engine idled as normal. When he shifted into reverse, the RPM's dropped and the truck seemed to try to move like it was in gear with the brakes pressed. This seemed odd although I am not a transmission guy. I did read something that said if these symptoms are present, check to see if the shaft from the tranny is rotating, if so, the problem may be in the transfer case. Is there any merit to this?

I'm trying to put together a sequence of diagnostics and trouble shooting for us and could use some input about the best way to go about it and any other components to check before dropping the pan. I plan to check the solenoids and sensors.

He did say the fluid was extremely dirty. I'd also read that in some instances this could be the problem. Possible? We plan to service the tranny regardless so we can change the fluid and check inside.

Any feedback is greatly appreciated. I'm trying to help him get this issue straightened before is causes him to need a new tranny......hopefully that isn't already the case.

Thanks

Jamieat

Okay, so we attempted to diagnose what the problem is with his reverse. He was able to get his hands on a OBD II scanner as well and there were no codes what so ever present, much to my suprise.

So, we dropped the pan and all I can say is WOW!!! The fluid was completely black and was extremely runny, very little viscosity at all. The filter was in decent shape and only minor presence of metal shavings on the magnet or in the fluid.

The factory "plug" that would be present if the pan had never been dropped was missing which indicated to me that the pan had been dropped at some point in the past. For what reason or when is unknown as he's only had the truck a year and if memory serves, it has about 240,000 miles so, it's probably a good thing it'd been dropped before, hopefully for a service.

So, we cleaned the pan thoroughly, cleaned the visible components, replaced the filter, and the gasket as the original had been misaligned just a tad and the bolts had nicked the edges of the holes and we had a new one on hand.

Put 5 Quarts of Mercon V in the pan, disconnected the outlet hose from the tranny cooler, started the engine, pumped out another 2 quarts, then added 2 quarts, and repeated this process until all approximately 13.9 quarts in the tranny and torque converter had been exchanged with new fluid. Reconnected the hose, started the engine, with the brake depressed, shifted down through all gears pausing for about 15 seconds in each one, and then repeated shifting upward until we got back to park.

Went for a test drive, truck shifted much better and drove fine with the exception of the reverse. It did grab just a little and if we got it rolling at all, it would grab enough on level ground to continue to roll as long as the RPM's were up. It will not move from a dead stop however.

When you shift into reverse with the brake pressed, the rpm's drop as if it's grabbing, and under the truck, I can hear the transfer case making a sound as if it's turning inside and can feel movement that correlates with the sound with my hand.

He'd had issues with the linkage connection before and we are going to test the position sensor next.

I just wanted to see if anyone had any advice or suggestions about what to check/diagnose next or some insight on what we should do.

He was unable to obtain a reverse servo retaining ring prior to us working on it so, we did not drop the manifold to see if the broken ring pieces were present or check the servo (he procrastinated about getting the parts).

Does the fact that it seems to grab at all mean the servo is intact? Should we check the line pressures as well? And, could this be in the torque converter and how to check?

Thanks and any help is appreciated.

Dirttracker18

This is a common issue with those F150 transmission. You are going to discover that a complete rebuild is in order as the reverse band is totaled and likely took out the drum. At that point there is no use in repairing it, just a complete rebuild. Sometimes they show early signs of slippage at which point you can sometimes get away with just changing the band. Typically at this point the drum will show major damage as well.

Sorry I don't have any good news for you. Drop by your friendly neighbourhood trans shop that has a good reputation and warranty.

Jamieat

I am aware that this is a common issue with these trucks.

I've been part of 3 failed overdrives, all with broken servo rings. All repaired and no other issues.

I am also aware that there are many possible causes for this type of failure including but not limited to that which you mentioned.

He had no prior slippage before the reverse went out. Then only thing we can pinpoint was that his wife.....no other comment......put the truck in drive while still rolling backwards. This is when the linkage popped off the positioner. It was only a matter of days until the reverse went out. I did notice he zip tied the connection back to the positioner and it seems to restrict free range of motion with the ball joint type connection. Also, the gear shifter in the console has stiffness to it and doesn't seem properly aligned. First step is were gonna replace the joint on the transmission range sensor adjustment. Then calibrate the Range sensor to see if this helps.

I've also read that low reverse clutch, reverse band, and/or low line pressure can cause this as well.

The No. 6 shuttle ball, main regulator valve, 1-2 accumulator seals, and the reverse servo, bands, and sun gear housing, and the transmission / transaxle main controls can all cause this type issue.

Unfortunately, atleast where I live, the possibility of "Drop by your friendly neighbourhood trans shop that has a good reputation and warranty.' is non existent. Thats the reason were attempting to rule out all possibilities first before a rebuild as if he were to take it to a shop, there most likely gonna say it has to be rebuilt regardless.

I'm looking for any advice on how to trouble shoot, check, eliminate, diagnose any possible fixes before dropping it at a shop. Least this
way, he is sure there is no other fix possible.

Jamieat

Advice????Anyone?

Shheeessshhhh, figured surely someone would have some insight.

Dirttracker18

I did, you kind of brushed me off. With what you described inside the pan, you have a serious issue there and it points to the weak reverse band giving up. You will not know for certain until you open it up. There is no guessing here. Go inside and see.

I'd appreciate hearing back after as well as to what you found.

FWIW, lots of people switch to drive from reverse while rolling. There is no reason for this to cause the linkage to come off and the TC slip will take the load unless you are at speed. Not a big deal, although some people make it out to be.

Jamieat

Well, she was rolling fast enough that it shut the truck off when she did it so, I'd assume she was rolling faster than an acceptable limit. Also, to my understanding, although people often to shift to drive while still rolling backwards or vice versa (I've done it before myself) this is not an acceptable practice per the manufacturers specifications for proper technique and could potentially result in damage.

Given that the linkage broke, it's repaired in a restrictive, out of spec fashion, I do see that there exists a possibility, especially since the indicator in the truck is restrictive and not completely calibrated, that the transmission range sensor could possibly be out of sync. There are two of them. And, one of the diagnostic symptoms, per the Ford repair manual, is no reverse.

I'm not saying your wrong and what you said is very likely a more probable issue than any of the others that I mentioned, maybe with the exception of the reverse servo retaining ring or the sun gear which seem to be as/perhaps more common/prevalent than the reverse band. It could be a combination of several.

The way I tend to approach diagnostics and trouble shooting is to first analyze all potential causes, then rule them out 1 by 1 usually with the simplest first.

According the the Ford repair manual, with this symptom/issue, what we have proposed doing coincides moreso with their prescribed procedure than starting with tearing the transmission apart.

No offense, just really trying to be optimistic as much as anything, and along the way, I get familiar with some diagnostic procedures I was unaware of prior and gain some knowledge if I were to encounter this or anyone else perhaps, I could provide some insight.

That's kinda what I was asking for. Someone who may have or knew someone who'd experienced this issue and what were their symptoms, and how did they diagnose it, and what was the outcome or repair.

One thing I've learned for certain with these trucks, and I've had mine for 13 years is, don't think that there's only one cause for one problem and only one fix.

I feel like, given the nature of these beasts, unless there's irrefutable evidence convincing enough to disregard certain potential known causes, then I have to consider them all until I rule them out.

My friend is extremely tight on cash. What I'm trying to do is rule out any and everything within our ability so that, in the event that he does have to take it to a shop, he can feel confident knowing that we'd ruled out all other possibilities and that going to a shop was the only option left.

Hope this explains better my demeanor on the topic and thanks for commenting.

Dirttracker18

Don't get me wrong, I hope am I wrong on this.

FWIW I only notice slippage on mine prior to it giving out when I was stuck, in 4low and attempted to reverse out. Under normal circumstances I had no slip, until it let go.

Dirttracker18

Any update?

Biggbay

He probably sold it