Reed23

:wtf: I was talking to a guy the other day about putting in engine mounts for my 4runner supra swap. He was saying that bolting engine mounts to the frame is stronger than welding. Is that true? I don't think it is. In fact I would imagine that drilling holes through your frame would make it weaker, easier to crack and that you would lose some torsional rigidity from your frame as well (the ability to twist with out breaking). Anyone else have any input on this? Is this guy smoking the wrong type of tobacco?

Poul D'eau

If the person under the hood is good, welding is stronger. If the welder gets good penetration, the mount is one with the frame.

Now if the :monkey: welding undercuts the mounts or the frame, you can have some strenght issues.

jimbo74

depending on who you talk to, either is a safe choice, but only if done by someone qualified to do so......

Cebby

Do both - bolt then weld for good measure...

MTL_4runner

This is a basic engineering problem....bolt or weld?
Without getting too technical, in general welding is stronger.
If you are welding steel, then depending on the size of the weld it will be stronger than a bolt.

Welding on aluminum is VERY different and in general using bolts are better/stronger.

Also, a word of caution, especially with engine mounts, make sure to have some rubber/polyurethane isolation between the part welded to the frame and what you have bolted to the engine block. Never use solid metal engine mounts on a daily driver vehicle!!! You could fatigue or tear the weld right off the frame or shear a bolt over time.

X-AWDriver

Alittle off topic but still has to do with the welding vs bolting a piece on;what about sliders? I've heard both sides and haven't decided the route I'm gonna take.

weldpro

Well said!!! I agree completely. What does Toyota think...hhhhhhhhmmmmm.........well they weld every mount I have ever seen(exception- the early LC trucks). The bottom line is welding is safe , and the normal means that every major vehicle manufacturer uses for the motor mounts pads.

To the guy about the sliders. There is a really excellent way to bolt on sliders however it would cost alot of cash to have done. This would involve drilling through both sides of the frame , and welding in sleeves (welded on inner & outer frame rails). Just think of how a steering box is mounted to give yourself a better idea. Now as you can imagine this would take considerable time to do hence the big money to do the job! I DO NOT reccommend doing a bolt on job any other way. The proper way is to weld sleeves , and anything else goes against all frame modification standards that I am aware of . Auto manufacturers put out standards for frame modifications for trucks (specifically 1/2 , 3/4 & 1 ton) in regards to custom beds, boxes, fifth wheel hitches , normal receiver hitches- basically anything that will require modification to the frame. These standards tell you when , where , how , what not , etc, etc. basically the in & outs of frame modifications.
To answer your question in short- I could mount my own the bolt on way since my labor is free. However I have chosen the weld - on style due to simplicity & strength. If for any reason you need to take them off the easiest way is to use a sawzall (cake walk- really). Just be sure to use really good eye protection.
Hope this helps,
Richard Stubbs