IFS vs SFA 'burban

[DaveNay]

So, I'm pretty sure that I've narrowed down my selection of a new truck to a Suburban 2500 with either a 5.7 gas or a 6.5 diesel. Currently I am thinking a 1999 Suburban 2500 with the 6.5 diesel would be my top choice.

One thing I am still pondering though is if it is really worth while to consider an older model with solid axles. I am not convinced it is worthwhile to go with a 20 year old truck for the type of use I need. I really don't see us doing anything more extreme than logging or fire roads and basic family camping. I am not planning to build a rock crawler and a suburban really isn't the right vehicle for that regardless of it's suspension design.

Is there any compelling reason to go with a SFA in non-extreme situations?

 

[DaveNay]

Well, I think this thread give pretty good perspective.

http://www.expeditionportal.com/forum/threads/72913-IFS-really-that-bad

Anyone who wants to add to what is stated there, I'm willing to listen but it looks like there is no real advantage to me to go with SFA.

 

[SDDiver5]

I didnt look at the other thread but a solid axle will be better if you plan to tow and rock crawl. But, from what you have stated in your first post, IFS would be just fine.

I have IFS on my truck and it does the job perfectly.

IFS has a smoother ride as well.

Good luck.

EDIT: Ok now that I actually clicked on the link...
What I said was more in general facts about IFS compared to a solid axle.

 

[aardvarcus]

I think the advantage of SFA in non-extreme situations is strength that translates into durability. Comparing a GM Dana 60 to GM IFS, I think most people agree that you would break the IFS before the Dana 60. Most people on ExPo aren't into the “let's see if I can tear it up” type of wheeling, it is more of the unknown situations you could encounter. Things break even when you don't intend for them to. That said, more things can break than just an axle. The vehicle is a system, and failure of any one component can leave you stranded.

 

[DaveNay]

I think the advantage of SFA in non-extreme situations is strength that translates into durability. Comparing a GM Dana 60 to GM IFS, I think most people agree that you would break the IFS before the Dana 60. Most people on ExPo aren't into the “let's see if I can tear it up” type of wheeling, it is more of the unknown situations you could encounter. Things break even when you don't intend for them to. That said, more things can break than just an axle. The vehicle is a system, and failure of any one component can leave you stranded.

I can accept all that, and as you say, the truck is an entire system and I don't think the benefits of SFA (for me) are worth having the rest of the truck be that much older and prone to problems.

 

[dragogt]

What I like about the sas is the KISS principle of it, a lot less that can or will go wrong with d60 vs the ifs..

Sent from my SGH-M919 using Tapatalk

 

[locrwln]

Yeah, but no suburban came with a d60 front. Not saying you can't put one in, but everything from roughly '78 to '91 was a GM 10 bolt whether 1/2t or 3/4t.

To the OP, for your uses, the IFS will be fine. I would look for a 3/4t surburban though, you can at least get a locker for the 9.25; whereas the 1/2t front diff is not considered strong enough and unless something has changed, no one has a locker for it. Not to mention, I don't think a 10bolt rear axle (in the 1/2t) is strong enough for a suburban especially if it is loaded regularly

I use the hell out of my IFS truck, refer to my build thread to see where I have used it.

Jack

 

[dragogt]

You see where I said SAS right..

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[DaveNay]

To the OP, for your uses, the IFS will be fine. I would look for a 3/4t surburban though, you can at least get a locker for the 9.25; whereas the 1/2t front diff is not considered strong enough and unless something has changed, no one has a locker for it. Not to mention, I don't think a 10bolt rear axle (in the 1/2t) is strong enough for a suburban especially if it is loaded regularly

Definitely on the hunt for a 2500.

 

[k9lestat]

i would suggest after having to replace one before, if you get a 99 suburban it will more than likely have push button t-case. if you find with a manual t-case(dont know if there are any) i would do what i needed to do to the truck to make it manual. because if it electric shift the computer will only recognize the electric one and that could a problem if one new or used cant be located. i personally ran into this situation. i was 3 hours from home and had to pay a heavy tow bill to get it back home.

 

[Erik N]

I own each, both are 2500's.

The '88 has a 3 speed tranny. I like the tranny on the '96 better.

'96 is more comfortable. Better dashboard. Agree about the pushbutton transfer case, but it hasn't let me down yet. The 454 pulls well and sounds great.

I get compliments on the '88 every time I use it (which is only 1-2x a year). It is much more "trucklike." It is underpowered at altitude. The EFI has a slight off-idle hesitaton that I cannot track down. The saying goes about old EFI's is "They always run, and they always run the same."

Both get 11mpg.

 

[aarolar]

The GM IFS gets most of its bad history from its 1/2 ton variant, the 3/4 ton setup is stronger and has way less changes of breaking but you don't get to hear much about it because there is 1 3/4 to every 10 1/2 ton with a high school kid behind the wheel.