Weld or bolt frame motor mounts (1 Viewer)

[Jdc1]

I am slowly installing a 2f in place of a 350 into a 72. The PPO removed the stock mounts on the frame and welded them in to fit the SBC.

I knocked the stock rivets in and am weighing my options at this point on welding the frame mounts into the correct position or using the stock rivet holes and grade 8 bolts.

Does anyone have any thoughts on which would be better in this application? The correct nuts and bolts would probably be stronger than stock rivets. Would welding the mounts in place cause undo stress on the frame over time? Am I over thinking this?

 

[reddingcruiser]

You are overthinking it (slightly). Plenty of things get welded to FJ40 frames with no failures. The stock mounts can be successfully bolted back on.

 

[Fast Eddy]

Bolt, then weld.

 

[tnkayaker]

^^This is what I did.

 

[73tlcv8]

I bolted mine back on. I don't know if you have messed with it yet but getting the nuts on the bolts was a trick. I ended up putting the bolts inside out and putting the nuts on outside the motor mount.

 

[sggoat]

x2 Fast Eddy

 

[Jdc1]

Thanks for the advice. I want to make sure that I am not hacking anything.

I haven't messed with it yet as I am still prepping the frame. I thought of the tight squeeze. Tomorrow night I am going to grind the mounts off and pound the remaining rivets through and see if I can bend a wrench or modify something to fit.

The more I tear into this 40, the more excited I get as its in really solid shape for our area. We are putting a 2F, H42 and split transfer in as well as disk brakes and probably powersteering.

 

[shelfboy1]

i have done several by bolting in the motor mounts with grade 8 bolts ,never know when there will be no more 6s and you have to go back to a v8.

 

[Howard705]

BOLT- it's always changeable and removable. Evertything on cheap new stuff is welded-cheap/quick/easy/throwaway

 

[Fast Eddy]

The previous two posters apparently don't have an angle grinder.

 

[broth9640]

I vote for Bolts mainly for aesthetics reasons. Most people bugger up their welds (myself included) and it looks like garbage. If you can lay down a solid bead that looks nice or pay a pro then I vote for Welding. Most people don't care, but those are the details that make it a nice job V.S. average. I drool over perfect welds! Just My opinion

 

[Pin_Head]

The previous two posters apparently don't have an angle grinder.

X3

(just to keep my post count higher)

 

[Howard705]

Look at all these parts on Heavy trucks-semi tractors-cement mixers-ets-spring hangers/crossmembers/mounts-all bolted-only welds usually if the frame is lenghtened/shortened-on the framerails-all these parts made to be serviceable-changeable.

 

[Fast Eddy]

Heavy-duty rigs often have heat-treated alloy frames, so you don't want to weld to them. Different animal.

 

[Pin_Head]

Heavy-duty rigs often have heat-treated alloy frames, so you don't want to weld to them. Different animal.

X4 ...

 

[Tools R Us]

Bolting them will work just fine, no need to weld.

 

[cruisernerd]

If it were me doing this I would use bolts. I would avoid welding to the frame as I have heard dmv doesn't approve. But I would tack the nut to the bolt threads for insurance.

 

[hairy_apple]

Why would the DMV not approve of welded on motor mounts?

I've never had the DMV care about anything other then that the VIN on the paperwork is the same as the VIN on the body and frame. I had one look for an engine tag once but I said I don't think the 40 ever had one and she OK.. OH OK.. and that was that.

 

[cruisernerd]

I'm admittedly not an expert, but I was under the impression that welding on a frame was frowned upon. It is one thing if a journeyman welder does some, but if a guy pours some farmer grade nasty welds and you need to get an inspection, you might not pass. I was also under the impression that any welds and only be parallel with the frame rails and not run perpendicular to the rails.

 

[B y r o n]

I always try and go with the least destructive option or the one that is less likely to cause future headaches. Not being a professional welder I made my own frame mounts when putting in my V8 and bolted them to the frame. Heat can do strange things to metal; make it stronger in some, weaker in other and brittle in others. I've never heard of grade 8 bolts failing but I have heard of welds failing. I don't think the factory rivets are as sturdy as grade 8 bolts and they never seem to fail so my vote goes to bolting.