A fix for stripped threads on a 617 oil cooler.

[P.E.Haiges]

The oil cooler on the 617 engines is all aluminum. So sometimes the threads on the cooler and the steel nuts on the hoses diffuse together. When the nuts are turned to remove the hoses, the soft aluminum strips off the cooler thread and sticks in the nut, thus making the cooler unusable.

Since the coolers are very expensive, a fix can save a lot of money.

Here's how I did it: I had an extra cooler that leaked so I sawed the threaded nipple off and had it TIG welded onto the cooler that didn't leak. I cut the stripped nipple off next to the hex section so the two hex sections could be welded together This is because there was more parent metal in the hex section to weld to. Cost to weld was $10 and well worth it.

To remove the aluminum from the threads in the nut, I heated the nut, rapped it and most of the aluminum flew out. Then I scraped out the remainder. The heat broke the bonds.

P E H

[vstech]

Originally Posted by P.E.Haiges

To remove the aluminum from the threads in the nut, I heated the nut, rapped it and most of the aluminum flew out. Then I scraped out the remainder. The heat broke the bonds.

P E H

wouldn't it seem reasonable to heat the nut prior to removing any oil cooler lines then? maybe heat it slightly, then quench it with some oil on the lines?
John

[signalredcoupe]

I used anti-seize on both ends of the oil cooler lines upon installation. That should do it. Paul.

[Eskimo]

I've not done it myself, but I've read of someone repairing such a cooler by cutting the aluminum fittings off of the cooler, drilling and tapping it, and then installing steel fittings (after flushing out the chips from drilling and tapping).

I found it here. Search on the name "Kmetz" to locate that section.

I'd be curious to see if those part numbers still work, and if so, how much they currently cost. If they were available and cheap, I'd consider setting aside a couple of sets against possible future need.

[jim16671836]

I think that their is someplace that sells just the threaded portion and that it can be welded on... Jim

[jbaj007]

Read post #5: new ends on oil cooler lines OM603 '87 300D turbo Ouch!!!!

Credit: Brian Kmetz

[tangofox007]

Originally Posted by jbaj007

Read post #5: new ends on oil cooler lines OM603 '87 300D turbo Ouch!!!!

Credit: Brian Kmetz

That's a great option. The nipples are the same as the ones on the oil filter stand (where the cooler hoses attach.) No welding required and you eliminate the aluminum nipples all together.

[signalredcoupe]

Originally Posted by eskimo

I've not done it myself, but I've read of someone repairing such a cooler by cutting the aluminum fittings off of the cooler, drilling and tapping it, and then installing steel fittings (after flushing out the chips from drilling and tapping).

I found it here. Search on the name "Kmetz" to locate that section.

I'd be curious to see if those part numbers still work, and if so, how much they currently cost. If they were available and cheap, I'd consider setting aside a couple of sets against possible future need.

That's exactly what I had to do. Even holding the fitting on the cooler while loosening the nut on the line, I snapped the end of the cooler fitting inside the line. Took the fitting off of an extra oil filter housing & drilled & tapped the cooler. I still didn't trust the newly tapped aluminum to handle a large amount of torque, so I added a bit of JB weld to it. It's been fine so far. Paul.

[Stevo]

For those with a 616 it might easier too throw away the oil cooler and fit the o/f housing with a very short "in and out" U or find a Euro o/f housing, or figure out how to simply plug the oil cooler holes. I know this has been discussed in length but Euro 240Ds don't have oil coolers so why would US versions need them. There are allot of jobs (removing the IP) that are way easier to do without those pesky oil lines. Plus its one less thing to fail.