Thoughts on trans "fix in a bottle" for emergency?

[Cubey]

I'll try to keep this brief (I'm bad at that usually).

I am a full time RVer and my 37 year old Ford C6 trans is going bad, 3rd gear is slipping into gear but stays there fine once there. Reverse slips badly when trying to back up. I haven't totally lost 3rd or reverse yet but I'm now staying on back highways, manually shifting from L to 2 and staying around 35mph max (with hazards on) to try to prevent total failure.

It's less than 20 miles to trans shops, but it's hard to find one that can support a big vehicle, and they ones they do are all backlogged by a week or two.

I have one currently lined up for next Wednesday (since this past Monday) but I'm second guessing it now, their lot is very small/crowded and I'll have to find somewhere to store my cargo trailer since they'll have no room. I have another shop in mind but they are totally closed on weekends, so I can't ask until Monday. I might opt for them instead but then have to wait a week or two before they can do the job. But they don't keep their lot a crowded mess (at least based on Google street and satellite views) and they appear to work on RVs since there are buses and RVs in their lot photos.

Money is super tight with the foregone conclusion of a ~$2000 trans rebuild (but do have credit cards I can fall back on in a pinch, but that's a last resort) and there is cheap camping less than 20 miles out of town (opposite side from where I am right now) so I might need to just make that drive and wait out being able to get in to the other shop, depending on how much they estimate they'll charge. Some shops want crazy amounts for a C6 rebuild. The parts are cheap and mostly easy to get still, $2700-3500 is grossly overpriced even for built up one.

So far, I have not put any additives into it, except for 1 bottle of Lubeguard a year ago, so it's basically running on pure ATF (Valvoline Dex/Merc). But I'm thinking I might have to bite my lip and put in some additive (probably Lucas) to tide it over for an extra couple of weeks and an extra 40 miles or so. I know that'll make the cleanup job worse for the shop, getting out that gummy crap, but.... maybe I should put some in anyway? I know the transmission is done for and needs rebuilding based on it's age alone, so that's gonna happen regardless.

Thoughts?

 

[ripcord]

The C6 typically starts not wanting to go into reverse and drive when cold due to square cut seals on the apply pistons that get hard and stop sealing well. You may see some temporary improvement with Lucas and it won't gum things up, just make the fluid thicker. I really doubt if the builder would even notice.

Are you sure that the tranny is not low on fluid? Low levels can cause slipping, too.

 

[B1974]

I'd try it just for curiosity's sake. It's not going to hurt anything at this point and who know it just may work.

 

[B1974]

Valvoline Dex/Merc

Are you sure it's not type F?

 

[Cubey]

Are you sure it's not type F?

The dipstick says to use Dexron-II and has the Ford logo.

 

[Cubey]

The C6 typically starts not wanting to go into reverse and drive when cold due to square cut seals on the apply pistons that get hard and stop sealing well. You may see some temporary improvement with Lucas and it won't gum things up, just make the fluid thicker. I really doubt if the builder would even notice.

Are you sure that the tranny is not low on fluid? Low levels can cause slipping, too.

It goes into L/1st and 2nd fine, 3rd and reverse are the problem. Reverse is really bad, shutters like crazy. 3rd just delays then stays.

Depends on the additive used if the builder will notice. This guy points out additive swollen seals in a trans. No clue what the customer used.



I will stay away from seal "conditioners", which is why I'm eyeing Lucas. It seems to just thicken things up, but not make seals squishy. I put some some Blue Devil power steering stop leak crap in last summer. They guarantee it to stop leaks or your money back. It did stop the leak ... for 24 hours. Then the seals totally busted loose and it leaked like mad. Blue Devil won't even respond to me about it, much less give me my money back.

I did notice the ATF low recently on a very long drive, it was at the upper add dot, so slowly I topped it off with the same Valvoline Dex/Merc it has. I dropped the pan, drained the torque converter, and replaced the filter in 2020, roughly 6,000 miles ago and gave it fresh ATF. The 3rd slipping only showed up this month, but I did notice mild slipping in reverse last winter (2021), so I doubt that had anything to do with the fresh ATF. It's an old trans with bad seals.

 

[Cubey]

I replaced the pan in 2020 also for a cheap chrome finish steel pan that has a drain bolt, so I can easily drain a bit of fluid before adding in the Lucas. I carry lots of tools like drain pans and such so it's no big deal to crawl under and do that.

I guess I'll see what the preferred shop I want to use now says on Monday about how soon they can get to it. If it's gonna be two weeks, I guess I'll get the Lucas and put it in and hope it holds out for an extra 50 miles/2 weeks. But mind you, it began noticeably sipping into 3rd about 900 miles ago just in the past month, but I had to haul donkey butt to where I was to tend do something. It has gotten slightly worse over that time but hasn't been totally lost (yet)

I do have RV roadside but who whats to have to deal with that crap, being stuck on the side of the road waiting for a tow truck, if it can be avoided with a $14 for a bottle of Lucas at Walmart. The cheap camping is under $10/night, vs $75/night for a motel or $45/night for an RV park. When we're talking about a week or two, that's a big difference in cost.

 

[danez_yoda]

AT-205 ATP reseal is one of the thing Scotty Kilmer likes for rear main seal transmission. He actually sprays it on all rubber in the suspension and under the hood. I would not be surprised if he drinks this stuff.

If the shifting problems are due to seals inside the tranny, worth a shot. All of these would get changes once the rebuild happens anyway.

 

[Chris142]

Many years ago I had a slipping 727 in a dodge. Drained some fluid out and put a qt of trans-x in it. It fixed it and was still going when I sold it.

 

[TheLastWord]

Much better luck with Lubeguard rather than Lucas

 

[Cubey]

Much better luck with Lubeguard rather than Lucas

It's beyond mere Lubeguard at this point. And it got a bottle of that last year anyway. The trans has 37 year old seals in it. I'm just trying to squeeze a few dozen extra miles out of it before I can get it into a shop for a rebuild, complete with a new torque converter and new larger oil cooler. The factory one is dinky and pitiful.

 

[Mgeorge]

I had a late 90’s diesel powered GM school bus that I took on a trip once. The guy I bought it from had just ran the trans dry because of a blown cooler line. It was shifting loud and a little rough, but still functioning. After a couple of hundred miles, that loud shift turned into a loud squeal and bang, the day after that the bus wouldn’t move at all. I added two bottles of Lucas and that bus shifted like new! Well, long enough to finish the trip.
Bottom line: Lucas will help in an emergency, but is not a permanent fix. It got me another 300 miles and saved a tow. Pick up a bottle or two for cheap insurance.

 

[ekrampitzjr]

Your C-6 dipstick says to use Dex/Merc. Around 1980 in new vehicles Ford phased out Type F, which (greatly simplified) did not have friction modifiers, so the transmission did not slip between shifts. The flip side was that the older Ford autos did not shift smoothly, but the old 1970s C-6s using Type F could go 300,000 miles if maintained, I think because of the lack of slippage. Using Dex/Merc changed the transmission behavior.

I wonder if Ford actually changed anything internally in later C-6s to support the change in ATF spec. My hunch is possibly not. I also wonder if adding some Type F might actually help your situation. But this is a guess and take it under advisement.

 

[Cubey]

I had a late 90’s diesel powered GM school bus that I took on a trip once. The guy I bought it from had just ran the trans dry because of a blown cooler line. It was shifting loud and a little rough, but still functioning. After a couple of hundred miles, that loud shift turned into a loud squeal and bang, the day after that the bus wouldn’t move at all. I added two bottles of Lucas and that bus shifted like new! Well, long enough to finish the trip.
Bottom line: Lucas will help in an emergency, but is not a permanent fix. It got me another 300 miles and saved a tow. Pick up a bottle or two for cheap insurance.

Considering I drove it 800-900 miles after it was already slipping into third says it has given it's all. I only really became worried when I had to back up several times to turn around in a narrow, dead end parking lot, due to having a small trailer, and it was slipping really badly. Since then, I have been keeping it out of third to avoid total destruction. Who knows, a bottle of Lucas might get me through the summer (~1800 miles) but there's no telling. It's not the best time and place to deal with a rebuild but oh well.

 

[clinebarger]

Direct Frictions are smoked which are "On" in 3rd & Reverse. No additive will make a difference.

Once the Friction material is gone.....The Clutch is now Metal to Metal.....Making metal that's getting circulated throughout the unit. This can also happen while in 1st & 2nd gears because the Frictions warp/dish causing them to drag while not applied/overunning.

These old 3 speed units & hard parts to build them are getting scarce, Kind of foolish to run one with a major issue that can/will damage other parts of the unit.

 

[Cubey]

These old 3 speed units & hard parts to build them are getting scarce, Kind of foolish to run one with a major issue that can/will damage other parts of the unit.

Well it's a long story but I'll just say I was already needing to make the trip but then had a good reason for hurrying and the problem really popped up worse during the hurrying, so I didn't have any choice by that point. I'll keep what you said in mind. I guess I'll stick to staying out of third gear and go 35 tops since it's all back highways without super heavy traffic, and not very far. If it's not being run then it can't wear out more, i figure.

Some have said it's a seal leaking problem while others like you say it's a clutch material issue. I'm leaning more towards it being the clutches.

 

[ripcord]

You can take what clinebarger says as gospel. He's our resident transmission guru.

 

[Cubey]

You can take what clinebarger says as gospel. He's our resident transmission guru.

I was already suspecting it, so it's not a shock. I'll just keep on doing what I did last week for the previous 20 miles, go 35 in 2nd and just let everyone pass me. On the two lane highway, I moved to the shoulder to help people see it was safe to pass when a small line piled up behind me and the opposite way was clear.

 

[clinebarger]

Seal Leakage can/will cause the Clutch Pack to burn down.

There are too many variables at play to say whether or not you'll make your destination.

 

[Cubey]

Seal Leakage can/will cause the Clutch Pack to burn down.

There are too many variables at play to say whether or not you'll make your destination.

I see.

Well it's about 20 miles to the shop i have lined up for Wednesday but reconsidering now. I'll know better after i call the preferred one on Monday. Both are in the same city, on the same street even, just a few miles apart.

Tomorrow, I have to leave where I am now. I've overstayed and they want me gone. (a parking lot). They have been civil about it, so no drama, they just will have me towed if i don't leave.

Whoever is actually in charge is like of a jerk though because they refuse to ever contact me despite repeatedly trying to ask permission through the underlings.

But whatever, I'll figure something out for the next few days at the very least. If it totally craps out in the city before a shop will take it in, at least I won't have to get towed very far. I have roadside so it won't cost me anything for the tow.