IFS offroad durability

[Roy Dykens]

Does anyone actually wheel their trucks with the factory ifs front end? I want to do the straight axle swap but want to keep the truck street legal and we have safety inspections every two years here. In the MVI guidelines it basically says no suspension modifications are allowed but obviously it's up to the discretion of the mechanic. With the amount of custom work needed I'm concerned that it would be tough to find someone to sign off on it as it is their license and their livelihood on the line if I did a bad job and it breaks and someone gets hurt.

So, that out of the way, is ifs any good or are the ifs lifts best for street trucks? I'm pretty hard on gear, I do mostly trail runs which can mean a good bit of mud as well as rocks. Looking for at most 6" of lift and 35" tires, maybe 37s down the road. Also, can you even get lockers for the factory front diff? Looking at torsen style diffs.

 

[thz71]

Half ton?

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[Roy Dykens]

Half ton?

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Yes, should have specified that. 97 k1500 Suburban.

 

[Trigger_guard]

The half ton (8.25) diff is pretty ****. No lockers available b'c it would just explode.

Lifts are a tricky one. For your use you want a 4in, as it keeps the front end in good geometry,. 6in will stress the CVs

A 4" suspension lift. And 3"body lift "should" give you clearance for 37s. But the 8.25ifs won't last long with real use, honestly 37s a bit too much for your 8.5 rear diff (being on a burb)

A possible compromise is swapping to a 9.25(3/4 ton) front diff. It won't be easy. There's no real documentation on it. But many have claimed to have done it

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[Roy Dykens]

Ok seems like I'll just grab a leaf spring Ford front axle and either the matching rear or a 14 bolt. Easier to make leads and shackles not look put of place. I think knowing how I do things that having to think about driving it easy would kill all the fun of off roading for me.

 

[98chevy2500SS]

Swapping in a 9.25" isn't really that hard. You just have to cut and re-weld the bottom support bracket and that's all. But I think the 9.25" diff is wider, so you would pretty much need to swap a 3/4 ton ifs setup, I could be wrong though. @Roy Dykens you are going to be better off with that Ford solid axle.

 

[Trigger_guard]

Swapping in a 9.25" isn't really that hard. You just have to cut and re-weld the bottom support bracket and that's all. But I think the 9.25" diff is wider, so you would pretty much need to swap a 3/4 ton ifs setup, I could be wrong though. @Roy Dykens you are going to be better off with that Ford solid axle.

I've been told that the 3/4 ton CV axles will fit into the 1/2 ton hubs. But that you need to have them shortened by I believe 1in each. I really wish someone would do a proper write up on this. (With pictures). Might save a lot of solid axle swaps

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[98chevy2500SS]

True, it would be nice if there was a write up when I did mine. Maybe by the end of this week I will get a write up on how to do this swap.

 

[Stillruns]

Roy,

You ask a fairly loaded question!

First think to think about is how is an IFS differs from solid axle. Solid axle is beefy and less likely to fail compared to the factory IFS, (especially when you add the weight of a Suburban body)!
But... IFS allows for better tire contact to the ground when wheeling through rocks or uneven ground.
Next on your list is you ask about "wheelin"... yes... many of us actually wheel our trucks... not just pavement pound but use them as designed. I can't speak for anyone but myself but I have a gold claim in the Bradshaw mountains in central Arizona and we go there a couple of times a month. Getting there requires about 15 miles of wheelin to get there. It's a mix of fast sand washes, a little boulder climbing and some fairly technical/tight sections. It's always changing some due to changing river flows so it's always a bit different.
Without comparing IFS to SAS, all I can tell you is my 94 k1500 extended shortbed has 290100 miles and the drive gear is all original factory stock. Always serviced by the book. Run pretty hard but never "stupid" abused and it's still going good after 25 years. Only thing I've changed is iI eliminated the stock axle actuator for a manual "4X4 Posi-Lok" and it has worked perfect for years. Suspension is all stock and I'm still running the factory size 265/75 X 15 tires. Yes, I have to be mindful of ground clearance issues and bemore careful about lines I attack but you would laugh at how many "built rigs" i have towed out over the years!

I'm not claiming I'm cool or my old truck is more than it is, I'm just talking about matching your gear to your needs and not wasting your hard earned money.

I did an SAS on my 98 Tahoe and yes, it was bad-a** but my 94 got to 75% of where my Tahoe went.
After buying the Tahoe, I put another 10k+ in it doing the swap with Dana 60s with lockers, a 6.0 ls swap with Allison 5 speed and t-case from a crashed truck, 4 inch lift on 35s and revalved, used Fox internal bypasses yes... it rooted hard.
So it really comes down to what you're willing to spend, what you'll really get from the investment and how much you're willing to lose when you sell It!

Your Suburban is a large mammal. It will need the beefiest parts you can afford. It could be phenomenal if well planned but you could probably build a tube chassis, street legal 4 seater that would eat the 'Burban for breakfast for not too much more.
The problem with money is you only get to spend it once!

Good luck on your quest!

 

[98chevy2500SS]

I agree with what you said about the IFS. I always hear people say, "SAS is the best," "IFS is g*y." I always disagree and defend the IFS. A couple weekends ago I went wheeling with my cousins on their trail and my truck did just fine, it's just in how you use it. Hell, it has a plow on it and does just fine. Some of the people that hate IFS probably abused the **** out of it and it quit on them.