Towing the RV backwards issue

[Tinman86]

We have a 22' Chieftain and it needs to get towed.

it's in our driveway and will move freely forward when it's in neutral.

When I try to pull it backwards it feels like it's still in gear and I have a very difficult time pulling it back.

is there some secret to this or a safety thing?

Thanks

[RobRV]

Block the wheels and disconnect the driveshaft! Usually the Tow Truck Driver will be prepared to do this.

[Nick-B]

This is a shot in the dark, but most (all?) automatics have a one-way sprag-clutch (looks like a big roller bearing) around the main shaft that lets it freewheel in one direction but engages, or locks in the other. If this is damaged or if the transmission was apart and they re-installed it backwards, it COULD explain your problem. Unfortunately, the only way to know is to dismantle the tranny.

Then again, I could be barking up the wrong tree but I can't think of anything else.

[Tinman86]

Since we have figured out that the tranny may be shot I contacted or local rebuild guy and he said that it is probably that the plates have welded themselves together because of no fluid and heat or that something major mechanical has gone bad.

it's a shame that the PO did not take care of this because I would expect more than 17k miles out of a THM 475!!

it's going on a flat bed next week for a 4-5 day stay with the tranny shop.

[wa8yxm]

Quote:

Originally Posted by Nick-B This is a shot in the dark, but most (all?) automatics have a one-way sprag-clutch (looks like a big roller bearing) around the main shaft that lets it freewheel in one direction but engages, or locks in the other..

I am familure with this type of overrun clutch, I have seen it on some equipment. I have worked on dozens of cars and trucks and have NEVER seen on in the power train however.. on the starter, yes (Standard part on many starter drives) but never in the drive train

In fact.. Have you ever heard the phrase "Georgia Overdrive"?

Georgia overdrive is .. Prhoibited in Georgia by the way, It means 'Coasting in neutral'

The device you describe (An over run clutch) would prevent engine braking and thus woudl be a "Georgia Overdrive"

Now. to the O/P... I can think of several things that might cause such a problem, including a failure of the parking brakes, and of the service brakes.

Best choice is a professional tow person who can, as described, disconnect the drive shaft or .. trailer the rig to the shop.. Trailering is always best, but not always possible.

[Nick-B]

Quote:

Originally Posted by wa8yxm I am familure with this type of overrun clutch, I have seen it on some equipment. I have worked on dozens of cars and trucks and have NEVER seen on in the power train however.. on the starter, yes (Standard part on many starter drives) but never in the drive train.

I'm afraid you are oversimplifying things by comparing a starter (a handful of parts) to a complex automatic tranmission. I have rebuilt several GM transmissions (Old Dual-range Hydramatic, THM200R4, THM400). When I said the sprag clutch is around the main shaft, I meant the internal main shaft of the transmission not the driveshaft. My aplogies, I should have been more clear. Also, engine braking in these transmissions is provided by the main band which squeezes around the primary drum (all internal) and provides a link between the input and output shafts when coasting. Without it these transmissions would indeed have a "Georgia Overdrive".

Tinman's tranny guy is possibly correct in saying the clutch plates are fused together from lack of fluid (the lack of fluid was mentioned in another post on this same issue by Tinman). It is an extreme condition but could explain the odd problem.

[Tinman86]

So I am wondering how hard it would be to pull the tranny myself and then take it to be rebuilt

any suggestions on this?

[Nick-B]

It would save you the tow charge and the R&R labor. It is not terribly complicated but you might need to raise the front of the rig to have enough clearance to slide the tranny out. Jacking up the front half of a 10,000 lb motorhome is not quite the same as jacking up a 4000 lb car. Gotta have a good HD floor jack and skookum jack stands to support it.

Crawl under there first and look at everything - if you think you can do it, you can.

If you want to do it, I can offer more pointers.

[Tinman86]

Nick,

i think I am going to try to pull the tranny myself.

I have 3 hydraluic floor jacks. a house jack and am going to borrow an ATV jack to hold the tranny.



When I look at it I see
2 hydro lines - going to the tranny cooler look simple to take off
the linkage for shifting
a sire to some king of selenoid looking device
the fill tube

not sure how and where to pull the drive shaft
not sure what to take off first that is holding to the motor
not sure how far I have to slide the tranny to the rear to get off the shaft


all tips and advice is appreciated!!

[Nick-B]

Quote:

Originally Posted by Tinman86 Nick, i think I am going to try to pull the tranny myself. I have 3 hydraluic floor jacks. a house jack and am going to borrow an ATV jack to hold the tranny.

Drop the pan and drain the fluid first.

When I look at it I see
2 hydro lines - going to the tranny cooler look simple to take off
Use flair nut wrenches - open ends will just round off the fittings.

the linkage for shifting - naturally

a wire to some king of selenoid looking device - thats the kickdown solenoid.

the fill tube - held in place by a bracket up on the bellhousing

not sure how and where to pull the drive shaft - start at the rear end and work forward - I assume it is a 2 piece shaft.

not sure what to take off first that is holding to the motor
remove the flywheel cover and remove the 3 or 6 bolts holding the flywheel to the torque converter. First mark the flywheel to converter position so you can put it back the same orientation. Then remove the 6 bolts holding the belhousing to the engine. Make sure you have the jack under it at this point. I use a looong extension(s) and a u-joint to put my ratchet back where I have clearance to work it.

not sure how far I have to slide the tranny to the rear to get off the shaft
only need about 2 inches to clear everything - there is no shaft sticking out the front like a manual trans. Keep a hand on the torque converter as they like to slide off when you are lowering the tranny.

all tips and advice is appreciated

[Tinman86]

So I did just about exactly as you outlined

only sheered off one bolt that held on the flywheel cover

I needed to remove the rubber bumper that was attached to the tail end of the tranny that was held up by a cross member but I got that off.

it's not all out yet I need to get the bell housing clear of the top then lower it down, then pull it towards the front so the tail can clear that cross member.

once it's all the way down then how do I get it away from under? My guess is that I need to jack the front I beam up and pull it out from the front of the MH.

Then off to the rebuilder....and I hope back in next weekend

thanks for your help..

[Tinman86]

Looks like I can't find a way to get the tranny all the way out and down without taking out the crossmember that holds the tail end of the tranny...bummer

got the PBblaster on it now and giving it a bit of time

Stone driveways and rain just enhance the experience...

[Nick-B]

Yeah, I was going to suggest that you'll probably need to remove the crossmember too. Gravel is a bummer, Bro. Been there - done that - no fun.

To get it out from under the motorhome, you MIGHT be able to drag in out with the high point of the bellhousing thru the front wheel well and the tires cranked all the way over for clearance - worth a shot. Otherwise jack up the front and the slide it out to the front, or try the wheelwell thing again.

[Tinman86]

after much..

I ended up getting it on the ground and on a piece of carpet and pulling it out behind the pasenger side wheel well.

then I had a cold beer

off to the rebuilder today