And here's today's project. I want to be able to pull the motor mounts out of the way so it's easier to pull engine, trans, and t-case as one unit. In past builds, the motor mount horns get in the way, so I decided to make them fully removable.

So I sleeved in some 3/4 OD tube so I can run 4 1/2" bolts to mount the horns.

Sent from my SM-G950U using Tapatalk

 

Nice idea. Frame horns always suck.

 

Drivetrain is hanging on it's own. Next up front suspension.

Sent from my SM-G950U using Tapatalk

 

Make those brackets out of angle and let the bracket itself take the weight of the drivetrain instead of the tension of the bolt. My $.02

 

They can be fancier than angle iron, but the concept is the same. Take the load off the bolts so that the bolts are doing the retaining, not supporting the entire load.

 

While I agree with you guys on taking the load off the bolts, 8 1/2" gr 8 bolts won't even bat an eyelash at that job. Besides, under power 1 side will be pushing down and 1 will be pulling up. If you don't want any shear loads on the bolts you'd want U shaped brackets wrapping around the top and bottom of the frame, which would probably suck to remove. The clamp load alone from that many bolts squeezing the brackets to the frame will probably keep them out of much shear force.

 

I had thought about wrapping it around but thought it added complexity without a lot of extra benefit. You really think it'd be a benefit over the one 1/2" grade 8 bolt going through the bushing?

I guess if they get loose, they would be at a bigger risk.

 

A little lip on one side would help with alignment on reinstallation.

 

I would weld a “heel” ledge along the bottom to maintain location when they get removed and will also keep it from falling out if your bolts came loose.

 

Fawkin Dale beat me to it by a minute. :finger:

 

I wasn't as concerned with torque as much as keeping the engine from continuing to the ground when you land from those sweet jumps. At least with a lip on it, it can't fall to the ground. You could accomplish the same thing by making your thru-frame bushings stick out the thickness of the bracket material. Then the bushing would take the load and the bolts would hold them to the frame. I'm sure I'm over-complicating it. It's a little compromise for piece of mind IMO.

 

FYI, @JohnnyJ your used tires have arrived. They look pretty good for their age but you will need to vulcanize one of them.

 

It takes almost 18,000 lbf to shear a 1/2" bolt, so x8 thats 144,000 lbf. I don't know how much air time it would take to generate that much force, but I think its negligible since you'd likely be the weak link and not the bolts. :finger:

And since I love to get enginerdy with this stuff, the clamp load of a properly torqued grade 8 1/2" bolt is roughly 12,000 lbf, so x8 thats 96,000 lbf. So I'd dare say those bolts will never experience any shear stress of significant levels. :deuces:

 

What bbaxj said but with math and numbers and stuff

:teehee::thumb:

 

Whoa, that was a shit ton of tech there. Had to make sure I was in the right place.

 

Dowels are for location, keyways are for stress, bolts are for holding shit together. You didn't even consider the moment arm to the CG of the engine from the mount point, or the fact that they'll pull threads before they shear. 4 of the 8 bolts do nothing with a down force, geez man, where'd you get that degree? Your calculations aren't even valid. :sonicjay: Draw a free body diagram before you try to get all enginerdy next time.(Patiently awaiting FEA stress diagram :teehee I don't care either way. I can't even spell wheelering. It'll be fine until it isn't. :thumb:

 

:thumb:
opcorn:

 

I like the dowel and tapered slot idea.

 

Use (16) 7/8" grade 12 bolts. Sleeve the frame. Slot it, dowell it. And then, booger weld the shit out of it.......

 

These things are taking up space in our warehouse. Thinking of taking bids.

Sent from my iPhone using Tapatalk Pro

 

How many free vulcanizing repairs are included??? :finger::finger::finger:

 

if there was a mount on only one side of the engine, there would be concern.

Fortunately, around 130 years ago they realized this and put mounts on both sides of engines, which creates a triangulated structure. For all purposes the mounts are rigid to the frame and there is very little tensile loading on the bolts because the engine creates a triangulated wedge when it applies force downward.

 

Didn't know there was a warranty. I couldn't come up with the scratch for another $1K in tires to run the Maxxis. Or maybe I couldn't justify.

 

I've run Maxxis. I went back to Reds.

 

They're probably fine for a lighter duty rig, sidewalls are probably comparable to the 42 trep from what I hear.

 

I've been around plenty of crawlers that have done well on 39 reds. I don't plan on doing any racing, so not worried other than the occassional slice that occurs. I've sliced BFGs, Goodyears, Intercos, and Maxxis tires.. it's bound to happen.

I do miss the 35 General short course tires I used to have. Those were brutes. I don't think I've ever worked with a tire with a thicker sidewall.

Wow, you've really let yourself go

:teehee:

 

I'm 4,800 pounds.

 

Wow, you've really let yourself go

 

:sonicjay:

 

4 39 reds fit in a suburban. Thanks again Jim.

Sent from my SM-G950U using Tapatalk

 

With room to spare to carry your sun tan lotion. :thumb:

And of course you have to mount one.

Sent from my SM-G950U using Tapatalk

Looks good. And always glad to help out. :nana: