Stripped out your transmission crossmember bolts? Easy fix.
08-08-2010, 11:12 PM
#1
Stripped out your transmission crossmember bolts? Easy fix. So I managed to strip out all 4 of my transmission crossmember bolts (somehow, rust I'm guessing). I did a bunch of searching here and elsewhere before tackling the problem. There is good info out there, but no central location. So I figured I'd throw it together real quick.
ASSUMING that the captive nuts that you bolt into did not actually rust out completely, it's an easy fix. The factory bolts are M10x1.5x30. You have two easy options, parts easily available at your local hardware store.
Drill out with a 25/64" drill (something that can drill through steel easily like a cobalt bit). Tap with a 7/16"-20 tap. Use a 7/16-20 bolt, 1-1.5" long. Make sure you use a washer too. Easy. The factory bolt, as mentioned is 30mm long (about 1.2"). The reason you can get away with a 1" long replacement bolt is that the factory bolt isn't threaded the whole way, the top 1/4" or so is "blank". 1.5" will work too because there is a lot of dead space above the captive nuts, so you're not gonna bottom out. I used 1.25" no problem.
Alternatively, you can use a 27/64" drill bit with a 7/16"-14 tap and bolt. This is a coarser thread and as mentioned, requires a slightly larger tap and bolt. This will be harder to drill out but shouldn't be too bad. This is coarser than the factory 1.5 thread pitch, but the -20 is finer, there is no exact match that I found.
As a second alternative, you could do something like a M11x1.5 tap and bolt, but unless you have a good fastener place nearby it's gonna be tough to find. M12 is easier to find but is a fairly decent jump up. I found the 7/16" stuff at the local hardware store (TruValue). Since 7/16" is just slightly larger (roughly .04") than 10MM, it takes 30 seconds to drill out (which is basically just removing the threads and not really drilling out any further than that). I did all 4 bolts in maybe 20 mins tops. It secured just fine and did not strip using the factory torque of 38ft/lbs (I've seen 37 and 40 listed as well, but close enough).
There ya have it!
Dope
ASSUMING that the captive nuts that you bolt into did not actually rust out completely, it's an easy fix. The factory bolts are M10x1.5x30. You have two easy options, parts easily available at your local hardware store.
Drill out with a 25/64" drill (something that can drill through steel easily like a cobalt bit). Tap with a 7/16"-20 tap. Use a 7/16-20 bolt, 1-1.5" long. Make sure you use a washer too. Easy. The factory bolt, as mentioned is 30mm long (about 1.2"). The reason you can get away with a 1" long replacement bolt is that the factory bolt isn't threaded the whole way, the top 1/4" or so is "blank". 1.5" will work too because there is a lot of dead space above the captive nuts, so you're not gonna bottom out. I used 1.25" no problem.
Alternatively, you can use a 27/64" drill bit with a 7/16"-14 tap and bolt. This is a coarser thread and as mentioned, requires a slightly larger tap and bolt. This will be harder to drill out but shouldn't be too bad. This is coarser than the factory 1.5 thread pitch, but the -20 is finer, there is no exact match that I found.
As a second alternative, you could do something like a M11x1.5 tap and bolt, but unless you have a good fastener place nearby it's gonna be tough to find. M12 is easier to find but is a fairly decent jump up. I found the 7/16" stuff at the local hardware store (TruValue). Since 7/16" is just slightly larger (roughly .04") than 10MM, it takes 30 seconds to drill out (which is basically just removing the threads and not really drilling out any further than that). I did all 4 bolts in maybe 20 mins tops. It secured just fine and did not strip using the factory torque of 38ft/lbs (I've seen 37 and 40 listed as well, but close enough).
There ya have it!
Dope
) 
08-16-2013, 12:19 AM
#4
Teching In
Join Date: Jul 2005
Location: warren, mi
Posts: 37
Likes: 0
Received 0 Likes
on
0 Posts
it says 66 ftlb in my 2000 service manual and 43 ftlb in my 96 service manual and 48 ftlb in my bmr torque arm relocation trans mount directions. hmmmm which to choose which to choose
