transmission oil cooler hose: torque for the jam nut on 90 degree fitting

transmission oil cooler hose: torque for the jam nut on 90 degree fitting: SOLVED

Hello forum.
One of my jam nut on the 90 degree fitting got loose and I lost some oil between transmission chase and 90 degree fitting. The steps to change the trans oil cooling pipes are in TM 9-2320-365-20-3 on page 697, but there is no torque indication. Only the torque for the hose is indicated: 94-104 lb-ft.
Do someone know the torque to tighten the jam nut?

I would not like to overclose the nut and to damage the transmission chase...

Thank you a lot and sorry for my bad tecnical english...

Christian from Italy!

They don’t even list a torque spec for it in the transmission replacement procedure where you remove and install those fittings from the transmission case. I would say snug enough so you cannot rotate the fitting when pushing on the hose fitting...

Ronmar said:

They don’t even list a torque spec for it in the transmission replacement procedure where you remove and install those fittings from the transmission case. I would say snug enough so you cannot rotate the fitting when pushing on the hose fitting...

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OK. Thank you.
The problem is that I am loosing oil right there, and I don't know how much can I tighten. Seems that would be a trial and error procedure...
Christian

90 degree fitting at the trans going to the oil cooler? The trans side of the elbow has an o ring. You can probably replace with a generic. The newer style ones also have an o ring on the flare side. If its leaking there and your elbow dosnt have the o ring in a groove on the flare then you can get a flare seal copper gasket to put in between the line and the fitting. The metal trans cooler lines can get hairline cracks at the flare and leak.

The hairline cracks suprman mentioned happened to me on a big trip to Seattle. Hydro shop in Flagstaff cut the end off, grafted another one on with a sort of female to female splice, and I was back on the road same day. I have no idea what torque they used, I think the german gutentight...

Hello!
The solution was simple: I tighten the nut between transmission case and fitting and leak stopped. Now OK for 300 miles.

Thanks for the support!

Christian

Happened today, 1000km from home. Frame and rear axle is full of oil, what a nightmare! Now I need to find some hydraulic hose shop to get 2 flexible ones... Loose about 2 liter of oil.

Of course on weekend, no one is working...

BTW: are the original hoses of aluminium or steel?

Christian

Suprman said:

90 degree fitting at the trans going to the oil cooler? The trans side of the elbow has an o ring. You can probably replace with a generic. The newer style ones also have an o ring on the flare side. If its leaking there and your elbow dosnt have the o ring in a groove on the flare then you can get a flare seal copper gasket to put in between the line and the fitting. The metal trans cooler lines can get hairline cracks at the flare and leak.

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I had temporary 1-inch diameter hoses made by my local hydraulic hose shop, cost ~$70 each.

Thank you! That I think is the best way to solve! Do you remember what kind of attachment they had? Jig or flat?

Don't drain your tranny, just pull the hoses off (only ~1-2quarts of oil will come out at the hose end/cooler), and take them to the hydraulic shop

Awesome! That's a good tip! Thank you very much!
Do you have a picture also of the other side of the hose?

Christian

f8617 said:

Don't drain your tranny, just pull the hoses off (only ~1-2quarts of oil will come out at the hose end/cooler), and take them to the hydraulic shop
View attachment 757793

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