1070 no go in 2nd and 3rdPS

RGMartin

Well-known Member
Finally got to a point in my other projects to get into it, owned it for a couple years. Pulled good in 1st and Reverse. Second was weak. 3rd was nothing. Only ran for under an hour after I put it back together, a few minutes at a time while I played with it, so I'd imaging it was like this when parked.

It has been a while since I took pressure readings, but IIRC, all were good except C3 in 2nd was only like 50#, and C3 in 3rd was near 0.

When I shimmed the valve to hold more pressure I got the C3 to go up a hair, but the gauge bounced wildly.

The PS was supposed to have been gone through just before it was parked 15 years ago. I found a where a mechanic had engraved the hours and date on the C1 disc hub. Under 100 hours ago in 1994.

What I found was a wrecked C3 pack, steel plates stuck on the center so hard I am going to have to cut them off. Sinterred discs that are worn to half thickness. The C3 clutch hub has some color to it(bluish) from being hot.

Any reason not to reuse the hub if the splines are good? Oddly parts aren't nearly as expensive as I was expecting(discs and spacers). The Hytran/filters will be more than the clutches and spacers.
 
RG,

Do you have the pistons out yet. If it an older 70 series it has the lip seals with heavy wire inside to act as an expander of sorts.

If it is that style if it were mine I would update the pistons to the latest design which is an O ring expander and a square cut seal. There is just no comparison between the sealing ability of the two.

I don't know how high you have the flo divider shimmed but 210 is enough and over shimming it to the extreme can create other problems.

Another thing for sure, always use new ferry headcapscrews for the c2-c3 chub assembly , be clean and use red loctite on the threads and even a little down the sides of the bolts.
 
I shimmed it up to 200, but didn't help any so I let it back down to 160-170.

The C2-C3 bolts were incredibly difficult to get out, I can see them being stressed by removal.

Thanks for the tip on the seals/pistons. Don't have them out yet to see what I have there. They may have been updated at its prior rebuild.
 
RG I would also like to add the failure you have described is a classic example of the damage that occurs when the C-3 pilot spool has been stuck on. I would clean the valve thoroughly and make sure all spools move freely. Your hub will be fine and I would follow Mel's advice. Also it would not surprise me if that C-3 piston has shrunk tight to the carrier and you cuss trying to remove it. In either case do not reuse it after they have been exposed to a clutch pack that hot. Good used new style pistons are readily available from salvage yards at a fraction of the cost of new and all they need is new seals installed. I don not think they will ever wear out unless damaged from heat such as happened to yours. Some how heat causes them to shrink and then they no longer slide freely in the carrier. Rod.
 
(quoted from post at 09:55:21 05/17/15) Also it would not surprise me if that C-3 piston has shrunk tight to the carrier and you cuss trying to remove it.

I was just coming in to post that. Trying to come up with a nondestructive method of removal.... I guess I'll just drill and tap it for some jacking screws. 200# of shop air isn't doing it with small pry bars around the edge.

It does have the new style pistons with nylon square rings, and rubber O-rings under them.

There were some sticky pilots. I took care of the valve body the last time I messed with it a year or so ago.

I guess one piston, some seals, bolts, gaskets, and a set of C3 clutches... Could have been worse. Yesterday I was ready to look for a whole 8 speed back half. This one has been a money pit, but I will know it is right when I am done.

Any reason not to use the A&I clutches/plates?
 
I have used a air chisel to split the piston to remove them. Have never used A+I plates so I can not comment on them. Rod.
 
I looked into the A&I clutch plates when I was going through my 2294 last year and found that they are no where near the same quality as the
factory ones, they are made similar to the pto plates in these tractors with a fiber surface glued on rather than the true sintered plates
like the factory uses. After emailing Rod he suggested that I go to the local salvage yard and sort through their used ones and find the best
ones. I came up with a complete set that had almost no wear when mic'd and compared to the the one new one that I bought as a baseline. They
were very easygoing on the price to compared to new. If you have a large salvage yard near you I would suggest that as a cost effective
option and getting quality parts as well.
 
Their pictures show the copper colored discs. If I order them and am not happy, my local dealer is real good about returns.

I'd go the used route, but no boneyards near by that handle anything that new or big.
 
Parts ordered except the bolts.

Found a used piston for half of case delivered.

The bolts have me puzzled, did the later tractors use bigger bolts? Parts books show 3/8x 2 1/2, but what I took out were 7/16"...


Probably get the bolts from Grainger, Under $2 each versus $10. Under $1 if you buy them by the box.

Are any of the other bolts problems waiting to happen?
 

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