6640 No Reverse

[Jackfr]

Well it finially stopped going into reverse.
We pulled the inspection plate on the floor of the cab and found that some of the linkage was badly worn and checking farther found the shifting fork worn and the reverse syncros chewed up see pictures. Looking down inside with a mirror nothing else seems damaged and the tractor goes fine in all gears in forward.
I was wondering if I should attempt the splitting of the tractor myself or send it out.
From what I'm reading in the service manual I should be able to replace the shift fork and worn linkage without a problem.
The forward reverse syncros it appears can be replaced from the front of the transmission, so I would replace the clutch at the same time.
These are the problems, it seems that I will have to remove the 7411 loader and subframe unless there is some trick that someone knows to rolling the front away with out removing it, though it looks like the sub frame would hang up on the trans as it is pulled away. The big question is does anyone know how much the rear of the engine will weigh and what I should use to support it so I can split the tractor? I have a trans jack that has a 850 lb limit and 24" lift is this enough? I know I have to block the front axle so the engine won't shift side to side and I would block the rear section solid and roll the front away. I have split other tractors (F5000, AC I600) in the past using rolling jacks transmission jacks or moving dollies but nothing this big.
Doing this job ourselves will save $1000 in shipping alone never mind shop labor.
Any suggestions would be greatly appreciated. Im at about 50/50 doing it myself/sending it out.

Jack

 

[Tw20]

Jackfr
If you have the time to split the 6640 I think you will get along OK. I would take the loader and sub frames completely off , it will save time in the long run.
If the tractor has A/C , the couplers should seal well enough to let you split the tractor. get a nice smooth concrete floor and a decent transmission jack to roll the engine ahead, use lots of jack stands and be careful, take your time!
Good luck! let us know how things turn out.
TW20

 

[svcguy]

You really do need to remove the loader and frame. While it may not be impossible if you leave it on, you will sure wish you removed it. I wouldn't trust your 850 lb transmission jack.The small transmission jacks are wonderful for a truck or chore tractor, but your 6640 is a bit hefty to be trying to roll around on a jack with that load limit. If nothing else is available, I would weld a simple, wide dolly that can accommodate a 12 ton hydraulic jack down in the centre and have enough surface to block which ever section you roll when split. We always crib under a tractor when we split it. Have never had one fall off a dolly or jack, but then it would be a lot easier to raise 3 inches than off the floor if it did. Looks pretty straight forward. Sounds like you have done this before, so I don't think you will have any problem. Bigger isn't any different, just heavier.

 

[mrman]

I am considering buying a 96 6640 that won't go in reverse. forward works fine apparently. cab & front end loader. 8800 hours. No history available other than it being government owned which hopefully means maintenance was up to date but also means there were many operators. I am an accomplished home hobby auto mechanic of 20 years but have never dabbled in transmissions yet. I read and ask a lot of questions before doing these kinds of things. I am adventurous but don't want to be unrealistic with my abilities. Price for tractor as it sits is $3000. I don't know much about this model but figure the loader alone must be worth most of that price so the risk would be pretty small if I bought it and couldn't fix it for a reasonable price.

Questions:
Does a person need to be an expert mechanic to break the tractor and fix the transmission?
Are specialized tools required?
Could I be into thousands and thousands for just the parts making this tractor best for parting out?
Are full step by step shop tear down/rebuild manuals available for a reasonable price or are they too $1000 as I have seen for some machinery?
thanks!

 

[whodat526]

first off you need to know what trans is in the tractor if it's a sl it could be a strecht cable and if its a sle trans it could be a solenoid out

and for 3000 dollars if it has a newholland loader it will be a model 7210 which is worth 3k alone if the tractor has any major trouble i would just buy another trans from a salvage yard for 2 k and still be in the tractor for 10k under value

it really is to hard to tear into

the tractor is worth about 7500 as is with the loader

 

[Jackfr]

I agree with whodat526 I'd buy the salvage trans and put it in. You might be opening a large can of worms when you open the trans as we did in our 6640SL 12 speed with manual reverser which came from a local town DPW. We got all the records and it was well maintained. The reverse gear when it failed fell down through the Front axle drive gears in the trans damaging them and then while it was apart we found the pto shaft and drive spline badly worn which we had replaced. The total cost for the new parts that were needed was well over double 2k. I believe the cause of the damage to the reverser was bad/worn linkage which didn't allow it to fully engage into reverse. So you might think of checking that also. We decided to send it out because of the size/weight/cab to our dealer for the repairs. Total bill ended up being much more then we expected due to the other damaged parts.