oil pan drain bolt repair

   / oil pan drain bolt repair #1  

yanmars

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Nov 29, 2009
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I have a Mahindra 4510 tractor. The oil pan has two drain bolts. One is stripped. The shop said they could not find an oversize repair bolt and as such had me order a new oil pan at over $300. I would have thought there would have been some other available cure. From memory I think since it is a manual front wheel drive assist tractor the oil pan has an indentation in the middle where the front drive shaft passes and hence a drain plug on each part of the pan.
I suspect the drive shaft will have to be removed also to replace the pan and of course a new gasket etc.
I am sure the pan is ordered and perhaps on its way but I did ask them to keep the old oil pan. At least if I can fix it I can use it as a spare should I ever damage the new one somehow.
I knew the thread on the pan was not quite right. I felt it once or twice during an oil change but it never leaked then and I did not lose oil between changes.
I realize it is too late to do much now but just asking for thoughts. I thought I recall seeing once a oil pan drain bolt with some type of compression rubber plug that worked in such a situation. Of course I would not want something that would leak or come out and lose all oil and potentially ruin the engine. Ideas? Thanks
 
   / oil pan drain bolt repair #2  
Pan threads striped they used to make an insert you put in hole then little smaller pan bolt.I used one of these on an ATV front axel but I can’t remember what’s it called worked well.Do some research you may luck out ??
 
   / oil pan drain bolt repair #3  
You could drill/tap for a heli-coil and use the same drain bolt. You could also drill/tap to match a different drain bolt.
 
   / oil pan drain bolt repair
  • Thread Starter
#4  
I mentioned a heli coil but they said the pan is too thin for a heli coil to work effectively.
 
   / oil pan drain bolt repair #5  
Depending on how difficult it is to remove pan.... Might be more cost effective to remove pan, and have bung in pan replaced or repaired.... The $300 price for new pan is just dollars in dealers pocket... Might look for independent mechanic to do repairs...

Dale
 
   / oil pan drain bolt repair #6  
Random thought without much coffee but I wonder if you could drill it out and just stick a rivnut in and get a seal?
 
   / oil pan drain bolt repair #8  
Different tractor - same type of oil pan design. My pan has a thick steel "blob" - like a really thick washer - welded at each drain plug hole. A whole lot more threads because of these "blobs".
 
   / oil pan drain bolt repair #9  
I would not trust a rivet nit to seal against the pan to not leak around it even if a drain bolt sealed to it.

Depending on how you want to proceed, there are several options I can think of:
•get a tap the size of you drain plug and clean/realign the threads to your drain hole and put in a new drain plug
•take your drain plug to an auto parts store and try to get an oversized drain plug. They come on several sizes (single over, double over and so on). These are similar to self taping bolts in that they cut new threads. Personally I consider these a close to last resort approach.
•I do not see that you have anything to lose by drilling out your drain hole and tapping it a larger size drain plug. One big caution is to do this right and get the drill bit size called for the new drain plug tap size!
•now a even more extreme repair. If you remove the pan, a good welding shop (typically tig welding) should be able to install either a backing plate thick enough to take threads or a nut with correct size threads inside the pan.
•as a spin off on the last above suggestion, if you can get the tractor to a welding shop or get a mobile welder person to the tractor and get the pan clean and dry enough, the welder nay be able to put a plate or nut on the exterior of the pan.
The first 2 and the last suggestions do not require pan replacement or even removal (at least now). The first 2 are fairly inexpensive.

One big caution if you use any oversized plugs is to always be sure the plug is inserted straight as they will cut new threads for lots of oil change cycles.
 
 
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