Sheared motor mounts
 

Ok guys I have a 97 zj 4.0 a few days ago the motor mount bolts on the drivers side sheared off. Well I took it to the local mechanic and they were only able to retrieve just one they put a new on in and the engine sirs fine ( for now ). I'm wondering if there is any mods that I could do without replacing the engine ( which was replaced 20k miles ago ). Any imput would greatly be appreciated.

Welcome to CF!

Those bolts were probably not grade 8 or were loose when the engine was installed. They can be drilled out and extracted, but because or space restrictions, the engine may have to come out to do it. I wouldn't trash the engine over a couple of broken bolts.

One of the coolest things I've seen done is to weld a smaller bolt to the broken one and remove it that way. That works well if the bolt isn't seized. If it was too long and bottomed in the thread, it'll have to be drilled out.

Yeah from what the mechanic said they are extremely seized or cross threaded like no other.. I've been looking into these bomb proof motor mounts.. I do have a 97 zj but the engine I replaced it with was a 4.0 out of a 00-01 wrangler I believe and from what I see its a type II 4.0. So should I look into getting the bomb proof ones for the zj or the wrangler. I know that the holes for the frame may not line up. Is that true?

Oh, wow! The mount bosses are in different places on the two motors. No wonder you had problems. Are you using aftermarket mounts? The later engine has the oil filter screwed into the side of the block, right?

Yes it does.. so do they make after market ones that will accommodate for them or should I get the wrangler ones and have the figure out new wholes for the frame? Wish the *** clown who put the engine in would have mentioned this!!!

Try Brown Dog motor mounts (they use 6 bolt holes on the block each side not just 3) I had to order a set for this 4.0 engine I bought for my 99 XJ (another 99 4.0 with 103,000 mi.). Here is what happened to it when they drove with a broken mount and hit a big pot hole. No repair for this hole lol.
Attachment 309361

My other problem I'd it's an 01 TJ engine that I was unaware of the bosses being lined up different than on a zj. So I'm trying to figure do I buy TJ motor mounts and go from there..

Try JB weld if you havent already scrapped it.
I have used it to do some INCREDIBLE things. give it plenty of time to dry. read the instructions. Make sure you insert the bolt while its still soft.

TIP: lubricate the bolt a little before you put it in the JB weld, so its easier to remove after it cures.

I'm going to use the Brown Dog mounts on that engine when it goes in.

Really? lol I dont think JB weld will work for that..

Uh...no, just no. I've rigged up my fair share of things but JB Weld on something structural like that, just don't. Its great for radiator repar or small stuff but nothing of this caliber.

Yeah I wouldn't use it anyways. I'm just wondering since it's a TJ engine in the ZJ if I could get the "Bomb Proof" motor mounts for the TJ how much modification would need to be done to the ZJ.

maybe get both and return the ones that don't fit?

Out of curiosity, I just went to Brown Dog Offroad and found they make super-strong motor mounts for Wranglers and Cherokees but NOT Grands. The 6-bolt mounts will fit the engine but NOT the body of the ZJ. I'm sure, however, you can drill holes to make them fit. The only reason they were changed was to balance the 4.7 in the WJ. It was a simple thing for the engineers, but started a nightmare for parts swappers.

Ok that's what I was hoping... I'll probably order the bomb proof TJ ones and have my mechanic do the rest. At least the engine will be supported a bit more than it is.