6x6 only engaging in reverse

seano11 · Apr 22, 2012

Had the m813 out today and going through some grease pits the 6x6 would only work in reverse it would really dig but in forwards it wouldn't do a dam thing Would this have anything to do with my air cylinder on my transfer case leaking ?

73m819 · Apr 22, 2012

could be, do you here a "clink" when the sprag shifts from forward to reverse, when the xcase is in forward, do you have air leaking

seano11 · Apr 22, 2012

Ya there's air leaking in forwards but the clunk isn't as loud as it use it be

patracy · Apr 22, 2012

Poppet valves need to be rebuilt on the trans. Take the trans tunnel off and it will be right in front of you. SECO in east GA had the rubber "pads" when I rebuilt one in my M51A2.

seano11 · Apr 22, 2012

patracy said:
Poppet valves need to be rebuilt on the trans. Take the trans tunnel off and it will be right in front of you. SECO in east GA had the rubber "pads" when I rebuilt one in my M51A2.

I just put a brand new poppet valve on so thats not it

73m819 · Apr 22, 2012

no it is the shift cyl. the air is comimg from the reverse poppet valve exhaust

doghead · Apr 22, 2012

I thought we covered all this before.

http://www.steelsoldiers.com/5-ton-up/86575-poppet-valve-top-tranny-leaking.html

seano11 · Apr 22, 2012

doghead said:
I thought we covered all this before.

http://www.steelsoldiers.com/5-ton-up/86575-poppet-valve-top-tranny-leaking.html

So then your saying that the air cylinder is whats causing the lack of forward 6 wheel drive ?

doghead · Apr 22, 2012

73m819 · Apr 22, 2012

very good chance, the cyl. is leaking, there is enough pressure to drop out of reverse because reverse helpes it to drop out, it goes to nutreal, but the seal is bypassing going into forward as it has to push into forward

No matter what the shift cyl. needs new seals

tie6044 · Apr 22, 2012

I had a 5 ton that did the same thing a while ago, I did a lot of searching and solved my problem with a hint I read: drain the t-case and fill it with diesel and maybe a little tranny fluid and drive it 30 miles or so and drain and re-fill with gear oil. It cleans a lot of gunk out and cured my issue.

seano11 · Apr 22, 2012

tie6044 said:
I had a 5 ton that did the same thing a while ago, I did a lot of searching and solved my problem with a hint I read: drain the t-case and fill it with diesel and maybe a little tranny fluid and drive it 30 miles or so and drain and re-fill with gear oil. It cleans a lot of gunk out and cured my issue.

I would do that but I just filled the dam thing with fresh oil so 145 for a new air cyclinder isn't that bad

73m819 · Apr 22, 2012

just rebild it, replace the two seals, while at it replace the control rod seal on the case

seano11 · Apr 22, 2012

Where do I go about getting a new seal tho ?

73m819 · Apr 22, 2012

white owl or any major mv parts vendor, give them the p/n from the tm, the poppet valves can be rebuilt, there are a few GOOD threads on it, Floridian-? had a good thread

seano11 · Apr 22, 2012

Which parts is it in that pic

73m819 · Apr 22, 2012

need to look in the tm, I would pull it apart, you should see the bad seals, find the numbers, at the same time find the case seal

seano11 · Apr 22, 2012

I think I`ll just order a whole new one then I can mark that off of things that could go wrong

MyothersanM1 · Apr 22, 2012

Call Memphis Equipment and ask for the 5-Ton declutch cylinder rebuild kit. It's a fairly easy rebuild, but he rubber seals are bit tricky. The higher lip/edge sides go toward the outside edges of the cylinder and must lay completely flat.

And, a couple more threads to assist you.
http://www.steelsoldiers.com/5-ton-up/18459-frustrating-809-series-sprag.html
http://www.steelsoldiers.com/5-ton-up/61817-5-ton-sprag-stuck.html

Hope this helps.

seano11 · Apr 22, 2012

MyothersanM1 said:
Call Memphis Equipment and ask for the 5-Ton declutch cylinder rebuild kit.

And, a couple more threads to assist you.
http://www.steelsoldiers.com/5-ton-up/18459-frustrating-809-series-sprag.html
http://www.steelsoldiers.com/5-ton-up/61817-5-ton-sprag-stuck.html

Hope this helps.

When I called them last week they had told me they stopped making the rebuild kit and just sell the whole cylinder now which kinda sucks

6x6 only engaging in reverse

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