Motor mount bolt holes won’t align
 

Need advice. I replaced my rubber motor mounts with poly ones. The last time I did motor mounts everything lined up perfectly. This time I got the drivers side to line up but for the life of me I can’t get the center bolt that goes thru the frame and into the motor mount to line up. I saw some older posts on here where guys have loosened the cross member to get the bolt to line up. That didn’t seem to work. I also saw where you can hog out the hole a bit. But I don’t think I can get the top bracket off without dropping the whole cross member. Any suggestions?

Re: Motor mount bolt holes won’t align
 

vardenafil,

This leads back to this thread you started a while back:

https://67-72chevytrucks.com/vboard/...d.php?t=854412

You have something misaligned with your frame, crossmembers, engine mount brackets, SOMETHING..

Even the experts on here don't have magical powers and super vision.. Poly mounts will NOT raise the engine and align the fan with the shroud. You're using that old unsuccessful technique called "shotgunning".. You're throwing parts at a problem, hoping something will stick and solve your much larger problem.

My first suggestion is take your truck to a reputable frame shop and have them do what is necessary to get everything back where it belongs.

Re: Motor mount bolt holes won’t align
 

I had new rubber mounts that I put on. The last time I did it, I had a heck of a time and worked on it for what seemed like hours. I couldn't get it to line up, but I'm sure it does line up. My wife asks me now and then what I got done with the truck, and I tell her a loosened a bolt or tightened a bolt, it took me all day. Anyway, the engine mounts, it was tough, but I finally got it lined up and it went in like butter. It took me 2 days to get one bolt in, it was the driver's side. On the second day, I still had the engine hoist on and lifted the engine just a fraction of an inch and moved it around and re-settled it a few times, and I used a crowbar and was able to shift the engine around just a little tiny bit, and the bolt went in. It's a good idea with the mount out and in your hand make sure the bolt goes in and screws with your fingers for the first few threads. You can also compare old and new mounts to verify holes are in the same places. Bottom line is for me it required patience and dinking around with it, and crawling under the truck, getting back up to shift the engine with the hoist, and getting back under the truck, repeat 173.5 times, it's good exercise.

Re: Motor mount bolt holes won’t align
 

David, I agree with you that on occasion, those bolts can be stubborn.. I, long ago, lost count of the number of motor mounts and transmission mounts I've replaced.. The ones that were the most difficult (some were impossible) were on cars/trucks that had been in a collision.. It doesn't take much of a frame kink to totally misalign a small bolt hole. In this case, forcing a fit will put a strain on the mount and it will soon fail again. On one particular motor mount job, I could not get the mount holes to line up, nor would the ears drop down over the bracket.. I removed the transmission mount bolts and wrapped a chain around the crossmember and extension housing.. I finally got the bolts to pass through ,, I hand tightened the nuts and when I looked at the transmission mount, the pad on the extension housing was over 2 inches to one side of where the mount attaches to the crossmember.. When I discussed this with the customer, I learned the owner had rear-ended a car about a year prior..... A few frame measurements and that uncovered a "diamonded" frame.

David, If you read the posts in that thread I linked, you'll see where vardenafil's engine sits very low, and is grossly misaligned so much that the fan doesn't line up with the fan shroud..

Re: Motor mount bolt holes won’t align
 

Could be something like a collision. Since vardenafil doesn't post very often and didn't follow up with that thread, it is unknown if there are any frame problems and unknown what makes him suspect the engine is too low. There is mention in other threads about fitting different shrouds, perhaps none of them actually designed to work with the particular radiator and engine configuration and that may make him want to mount the engine higher or lower to try to get the mechanical fan to work. I have several places on my truck where I struggle to line up bolts, but I think it is more my lack of skills rather than something like frame or cab damage. Some times the bolt lines up and I put it in and everything works smoothly, but the next time I take that same bolt off to work on something else, I can't line it up worth a darn and have to struggle with it.

Re: Motor mount bolt holes won’t align
 

I don't think it has anything to do with your so called lack of skills, how hard is it supposed to be to thread in a bolt you just removed 5 minutes earlier?

Is there such a thing as a bolt alignment specialist?

I had a heck of a time putting in a V-8 short block assembly after removing an inline 6, I did use the the origina unmoved IL-6 frame mounts and new O'reilly's V-8 motor mounts and the engine hoist was on a sheet of plywood on soft soil in the backyard and the hoist has a slow leak...I'm amazed I got the dang bolt in at all.
I stuck a flashlight beam in there and everything look lined up just fine too.

Re: Motor mount bolt holes won’t align
 

FWIW, my truck appears to be original, and the top-to-bottom fan to shroud clearances were way off. The fan was also way closer to the radiator and did not couple at all with the fan shroud. My FiL bought it in '73 and it always ran hot. He took off the stovepipe for carburetor preheat, put on a trans cooler and did other things. When we inherited it, I fought that 260° F coolant temp while towing for awhile, and posted a thread about the results. Looking at other people's trucks with big blocks, the engine is obviously too far forward. But it appears to be in the correct holes, based on where the motor mount perches are located. Who knows what has happened with a used vehicle? My solution was to fabricate a custom fan shroud, install a 19" fan with a severe duty fan clutch, and an aluminum 2-row radiator. After all that, it may have been as simple as installing that high-flow thermostat. The thing about problems like this, just like in drag racing, only change one thing at a time so that you know what actually made the difference. Yes, that's expensive, making that many runs down the strip. But do you want to win? This truck doesn't even approach hot on hills now, but we sold the trailer and bought a new motorhome, so all that work is now a moot point- until I have to haul a big trailer, and I KNOW that the truck will be OK.

Re: Motor mount bolt holes won’t align
 

I just changed out a left one in my 67 and had to lift the motor a touch and loosen the bolts from the mount to motor to get it started...

Re: Motor mount bolt holes won’t align
 

Which bolt are you guys talking about?

Re: Motor mount bolt holes won’t align
 

The single bolt that goes through the perch into the rubber motor mount.

Re: Motor mount bolt holes won’t align
 

That one!
Just like any other bolt that’s fun to get in, just taper the end at about a 45 degree angle and .Clean up the threads. When you screw it in it will self centre and go right in.

Make them look like a fender bolt.

https://www.ebay.ca/itm/353984495107

Re: Motor mount bolt holes won’t align
 

Maybe not that drastic but that's a good idea, just being careful not to cross-thread the thing afterwards.

Probably would have saved the neighborhood from hearing me cuss out that stupid bolt all afternoon. :banghead:

Re: Motor mount bolt holes won’t align
 

I been through that PITA more than a few times and don't want to deal with it ever again soooooo I commited this SIN:devil: :)

Re: Motor mount bolt holes won’t align
 

I'm feeling pretty good about my accomplishment!

Re: Motor mount bolt holes won’t align
 

I installed rubber cushions purchased from Classic Heartbeat, and my son and I spent 1-2 hours to get the 402 on right, with an engine hoist, until the upper and lowers CLICKED.

The frame's motor mount perches have play front to back, so I'd have start there before loosening a crossmember. Matter of fact, if memory serves me right, my crossmember only fits one way, dictated by the upper control arm brackets riveted onto the frame rails, and fixed nuts.

Speaking for an original 1971 frame anyway, factory rivets, BBC. Don't know why other years would differ, but probably some variances.

Re: Motor mount bolt holes won’t align
 

...that's cheating. :mad:
But only because I didn't know those things existed.
Fortunately I've only had to get that stupid bolt to thread in once in the last 30 years.
A testament to my skills as a mechanic.
HA! :o

If you're talking about being relieved after getting that stupid bolt to finally thread in, I think I went to the liquor store afterwards myself! :tim:

Many years ago when I first started learning how to wrench, I used to take my car to the old guy that ran a gas station and had an engine bay.
The index finger on his right hand had been severely injured by a radiator fan that had no fan shroud.
My truck didn't have one and I was going to fix that immediately!
Went to a salvage yard and got a shroud out of something but had to extend it over those razor sharp fan blades, so I got some of that plastic divider stuff from the garden shop and I feel a lot safer now.
You can modify just about any shroud to at least shield your fingers.

Re: Motor mount bolt holes won’t align
 

That's smart. I have a roll of that stuff, never would have thought to use it

Re: Motor mount bolt holes won’t align
 

I always looked for a shroud like this.


https://www.ebay.ca/itm/373583784888...iABEgIf_PD_BwE

Re: Motor mount bolt holes won’t align
 

I got the bolt in this weekend. Here is what I did in case it helps someone else out in the future. I basically loosened up all the bolts that I was working with. the motor mount bolts were barley threaded into the engine block. Each bolt was in only one or two turns. This allowed the motor mount to hang down enough where I could wiggle the bolt and get the thru bolt started. I just kept tightening each bolt in sequence a few turns until everything got nice and tight. I think my biggest problem was that on the poly motor mounts the center bolt doesnt pass all the way thru like on the rubber ones. They bottom out after several turns. So you cant just use a longer bolt because it wont tighten against the washer. Anyways thanks for all your suggestions. im off to the next project

Re: Motor mount bolt holes won’t align
 

thanks thats exactly what I did