Alum. Oil Pan Repair
 

Has anyone ever had success repairing an aluminum oil pan with a stripped mounting hole. :bigthink: I'm thinking helicoil method, but there doen't seem to be enough meat to be able to drill larger hole. I'm thinking JB Weld, redrill & tap... I'm thinking weld some aluminum in the hole, redrill, tap... also some other product my brother saw on some info.-like commercial, liquid metal (not sure of what it is...). Last resort, I'm thinking, anyone have a cast oil pan for a k341aqs for my 1650? Love to hear if anyone has had a successful method they could share. Thx!

JBWeld is an epoxy and is far weaker than the aluminum oil pan. It will not work.

Here is an oil pan I had to fix. I had a friend TIG weld the pan, building up the worn-down pads and partially filling in the hole. Before that, we drilled all the way through the pan with the correct tap drill size for a 3/8-16 bolt. Then after filling it in, the built-up metal was cut down to the correct height with a mill, then the tap drill was run through the hole from the back and the threads re-cut. Then small plugs were turned on the lathe, pressed into the back of the holes, welded in, and sanded off. All of the welding warped the pan a little bit, so I wet sanded it with the sheet of glass and sandpaper trick that I use to flatten heads. The CI pan would have been better, but I was running out of money. This didn't really cost me anything.

Before:
Attachment 6885

After:
Attachment 6886

I like to think that there isn't anything that I can't weld,grind,mill,fabricate,or repair,,,but sometimes it easier and cheaper to get a replacement. Unless it is not available. If it's just one bolt hole and you have the means to weld and re-tap go for it,otherwise buy another pan in good shape. Just my two cents.

If you do have to obtain another oil pan, make sure to get a cast iron one. I did that, when I owned a 1250. :beerchug:

Thanks you all for the input. It is only 1 of the holes. I got another 3/8 - 16 bolt 1/4 inch longer, and it allowed me to grab some more thread deeper, so I'm OK for now... I still think I'd like to try something like these sites are offering... Anyone ever try them?
http://durafix.com/ or http://www.aluminumrepair.com/ seems fairly simple, however, I've taken the easy route in the past with less than desirable results, If i do try it, I'll report my findings...
Thanks again!

Yea,
It works fine for small cracks/puncture like on a 12' fishing boat or a hairline casting crack. but in no way will it work for anything that really needs strength. BTDT. It has the strength of good solder, not a problem for stoping a leak or such, I've used it.
But the right way to fix the pan is like Matt did.
Heli ark the hole shut and re drill/tap.
With the kind of shake, rattle & roll that goes on with a 1650, you will just be wasting your time, and possibly take out the other threaded holes.

gotcha' seemed to good / easy to be worthwhile... thx!

My pan was worse than yours, except my drain hole was good. I bought a cast iron pan off ebay and paid under $30 including shipping. I'm glad I did. If you go that route, most of the pans will be listed as fitting the K301. It's the same pan. Just make sure it's for a Cub Cadet engine. Bids seem to start in the $10-12 range and end up around $20 or so. With shipping it's still a good buy.

I had an aluminum pan with 3 stripped holed. I drilled and tapped all 4 holes 7/16 Nf. I don't hsve a bottoming tap so I slugged the bolts the last 1/8th inch or so with the impact. They aren't comin out :)

Fine thread bolts in aluminum aren't a good idea. You may regret that someday...

Couple things come to mind here 1. Not a good idea bottoming bolts out in hole that is not tapped all the way to the bottom. If you ever remove them bolts the aluminum threads are coming out with the bolt. 2 You must have had to drill out the frame to put the 7/16 bolts into the pan which will cause a problem if you ever decide to go back to a correct oil pan. You will have quite a bit of slop there causing alignment problems. :bigthink:

The procedure mat used with a pressed in threaded plug is by far the best/strongest for this fix. I have used this fix many times in all types of metals, plastics, etc.. I'm not sure the welding the threaded bushing in was needed, I probably would have cut a coarse thread on the outside of the threaded bushing, and used a high temp lock type with at or just below max press fit spec for material used... I'm not trying to take away from matt's idea here, just another way to skin a cat... and the thread on outside of bushing is to hold the locktite, or whatever you use, a max fit pressed in plug is not going to come out anyway... but I would have used a high strength locker for that feel good feeling.

Another method I have used... make the plug your going to use, thread the outside of the plug, drill tap the hole your repairing, then thread plug into tapped hole to be fixed using high strength locktite.. If you can drill a hole to get a set screw to lock the threaded bushing in that's even better

I agree with the others jbweld alone will not hold up at the engine is heat cycled along with the vibration. Mcmaster and other places sell threaded bushings, they come as a standards, this would give an option to those without a lathe, mill etc.. Just read the directions careful when drilling the hole size for the threaded bushing as to much press fit and you will reduce the ID of threaded bushing causing your bolt not to fit.

I have not run into the problems with fine threads on aluminum, I have witnesses galvanic corrosion of aluminum threads (car engine brackets seem to be the worse) mostly from the elements kicking off the reaction.

Aluminum Oil Pan Repair
 

I recently had to repair two of the engine mounting bolt holes in the oil pan of my 1250. Both were on the left side. The pair of holes on the right side are in good shape, and I don't like to fix what isn't broken.

I bought a Power Coil thread repair kit a a local bolt supplier. The kit didn't come with coils long enough for the hole depth (~.975"), so I purchased additional coils that were too long & cut them off flush with a Dremel cutting wheel after installing them. I applied blue thread locking compound on the coils as I threaded them in. I'll let the thread locker cure before putting bolts in the new holes.

I have access to a vertical milling machine at work, so I used it to center the drill bit & tap to repair the holes & threads. In the process, I carefully measured the dimensions & documented them overlaid on a photo of the oil pan. I hope this information is helpful to others reading this thread.

Pitch the aluminum POS and grab a cast iron pan.
Picked one up off e-bay the other day for $17.
If Ya have to pay someone to screw around w/the alum one, it's gonna cost a heck of a lot more.

I have 5 QL's and just swapped out the last alum pan for a CI one.
PLUS, in really cold weather, you can slap a magnetic heater on 'em!

I've heard quite a few times that Time-Sert is the thread repair system to use, although I've used Heli=Coils several times with good results.

Hello RMidgett,

Was the hole pattern truly not rectangular? I find that VERY odd and wonder if it is supposed to be 4.875 x 7.625. I want to make a fixture to mount the engine cradle rails to perform the modification with the cross member welded in.

How did the helicoils hold up? I'm about to do the same.

Thanks,
Kevin

Hi Kevin,
I'm sorry for the slow response.
I was surprised by it, too. I was very careful making the measurements. I used digital calipers to measure each hole diameter, then the inside to inside distance between holes, and then added one diameter to arrive at the center to center distances. This is the only time I've done this job, so I'm sorry I don't have an average of several to draw conclusions from. I suppose it's possible mine is odd.

The helicoils are working fine, no problems yet. Time will tell, though..the machine shakes like a Harley-Davidson now, whereas it was smooth prior to the repair job. I've tried tightening the bolts and ended up loosening them to minimize the vibration.

I tack welded my cross member in, then had to move it forward..something bumped into it while putting the engine back in..don't recall exactly what, but it did fit in the end.