tranny mount/crossmember- urgent help needed

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plugugly

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the kids 87 k5 continues to kick us in the nuts. Suddenly he couldnt shift to park. immediately I thought it was adjusting the 700r4.

nope. The damn bolts on the drivers side of the crossmember came off, and dropped that side off the frame. Its torn the trans mount as well.

Im guessing I need some spacers in there? they are gone , and there are spacers on the passenger side. Does anyone know if there are spacers on both sides of this mount? are the spacers all the same length?

Its a 6.2 to 700r4
 
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The spacers are on both sides and all of the hardware is the same size.

Be sure the replacement spacers go on top of the frame like the remaining ones are (or should be).
 
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spacers seem to go between crossmember and frame, not on top of the frame?


also, anyone know where to get them so I dont have to make them?
 
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plugugly said:
spacers seem to go between crossmember and frame, not on top of the frame?


also, anyone know where to get them so I dont have to make them?
Click to expand...

They don't go between the crossmember and frame, that's just where people often put them when they lift the truck. As an attempt to help driveline angles.

Do have an Ace Hardware? Many locations tend to stock heavy wall steel spacers in the nuts/bolts isle.
 
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unfortunately, the only ace nearby is pretty limited. Im looking through mcmaster now.

why would they put spacers on top of the frame? i dont doubt you, just seems kind silly design. I understand dropping it for a lift and driveline angles. Is it necessary with a 4" lift?
 
PrairieDrifter

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plugugly said:
unfortunately, the only ace nearby is pretty limited. Im looking through mcmaster now.

why would they put spacers on top of the frame? i dont doubt you, just seems kind silly design. I understand dropping it for a lift and driveline angles. Is it necessary with a 4" lift?
Click to expand...
It's for bolt stretch for clamping force.

I would never recommend spacers between the crossmember and frame. At least not the factory spacers, you're going from a lot of surface area contact to almost nothing. I bet that's why you have sheared bolts and a dangling trans.

Spacers aren't needed between crossmember and frame. Maybe on a blazer with a 6 inch lift. Definitely not needed on a 4 inch lift long wheelbase. The bolt spacers are necessary in my opinion. GM wouldn't have spent that money or time if they didn't need to.
 
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Bolts didnt shear, the nuts came off. I wouldnt put a k5 in the long wheelbase category.

ill have to check driveline angles without the spacers. If needed Ill just make a spacer from some square tube.

Thanks for the info. Still having a hard time understanding the point of the spacers though......


EDIT:
are there different height tranny mounts? is the standard 2638 the right one?
 
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bucket

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plugugly said:
Bolts didnt shear, the nuts came off. I wouldnt put a k5 in the long wheelbase category.

ill have to check driveline angles without the spacers. If needed Ill just make a spacer from some square tube.

Thanks for the info. Still having a hard time understanding the point of the spacers though......


EDIT:
are there different height tranny mounts? is the standard 2638 the right one?
Click to expand...

The spacers are needed for proper bolt stretch when tightened down. A really short bolt has very little room for stretch, making it more likely to break when loaded (like when the chassis flexes).

There's two different styles of mounts used. The '85-up style is a single unit and just one height.
 
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If you not comfortable with the spacers on the crossmember don’t look at the steering box bolts. lol

Also, keep in mind that when spacing the tcase down to improve the rear driveshaft angle, you are making the front driveshaft angle worse.
 
PrairieDrifter

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I didn't say a k5 was long wheelbase? I also said exactly what the spacers are for?

Also no offense but how would you know if the nuts fell off or the bolts sheared?
 
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bucket

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PrairieDrifter said:
I didn't say a k5 was long wheelbase? I also said exactly what the spacers are for?

Also no offense but how would you know if the nuts fell off or the bolts sheared?
Click to expand...

I'd guess that the nuts were on the bottom, then the bolts were left dangling in the frame. I've actually seen that before.

Whether broken or simply loosened, the spacers being gone or used between the frame and crossmember could have caused that.
 
PrairieDrifter

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SquareRoot said:
I don't know, they gave the infamous 305.
Click to expand...
It's fine in its own regards. Just probably not for a full size truck. They were only offering what the people were buying :rofl: Not so strange when you could get a v6 in the later trucks...
 
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