IFS really that bad?

[BurbanAZ]

I have a 92 K2500 suburban with IFS of course, i always hear how every says its so prone to breaking and how horrible it is. I had a k1500 suburban with ifs that i was pretty hard on and it did fine, but i only had it for a few years. I now have my 3/4 ton suburban with it and now that im getting into longer and longer trips i was it to be reliable. It seems to most of the people i hear talking about how horrible IFS is build mud trucks or rock crawlers or want some huge tire size and lift. I have run this truck on some hard trails and some decent trips and its done great, i plan on just staying with what i have pretty much (around 33" tires, no lift" because it works well. I go back and fourth on wanting to do a SAS with a dana 60, of course this would be stronger but also cost a bunch. So what do u guys think, is IFS really as bad as some say? is the 3/4 ton IFS alot stronger than the 1/2 ton?

 

[northfacetraveller]

I personally dont think IFS is that bad. It all depends on what you are looking for, everyone has a different opinion based off of what they are used to doing when they go wheeling, or good/bad experiences etc etc.. There are definatly pro and cons to each of them, and it all depends on what you are comfortable with. Honestly I think if you have driven IFS for years and have experience with it, I would stick with it. Especially with 33's. I personally like both of them, but I use them accordingly to what I am going to be doing. SAS swaps are not cheap, and although ************! Its hard not to consider the ridiculous cost as a factor in your decision making.

 

[bftank]

you will be fine with 33's

 

[BurbanAZ]

yea it sounds like u guys are thinking the same way i was. It seems almost like the SAS thing has become almost a fad right now like many things do, they go from being based in practicality to people doing them just because its the popular thing to do. Of course a solid axle would be stronger and last longer and be awesome but to justify the money it costs to convert it, even doing all the work myself, it would have to make a night and day difference.

 

[topofpalomar]

I've had Ford, Nissan, and Toyota trucks and now have a 2006 2500 HD Chevy 4x4 with IFS. None were perfect (the 3/4 ton 4x4 Ford front springs sagged so I had to add an extra leaf to bring it back up) but all of them did just fine in the end. Keep it like it is if it suits your style and put your extra money into fun things, like camping gear, etc.

Cliff

 

[arveetek]

I have 240K miles on my IFS rig, and haven't had to touch any of the front end components yet. Granted, most of those miles are easy pavement miles, but still.

The biggest drawback to IFS: if you want to lift it, it's expensive, and when it's all said and done, you haven't gained anything except clearance for bigger tires. You still have the same amount of articulation. At least with a sold axle rig, typically after lifting, you gain more articulation and better flex, as well as extra clearance.

Unless you're building a serious crawler or mud truck, stick with the IFS.

Casey

 

[shortbus4x4]

Stick with IFS unless you are going with big big tires. If you beat IFS on rough roads it will probably take a few more trips to the alignment shop than a solid axle rig would. I have worked and wheeled IFS rigs hard (and broken a few parts) and I think for what you are doing you will be fine.

 

[lstzephyr]

I would stick with it if it is what you have already. Just about anything can go anywhere you want to go anyway. I have been using a 1991 mercury topaz as an explorer lately!

That said, the ifs really does suck. I have had to replace all kinds of parts on the k2500 ifs and I wouldn't take one much farther than a gravel road personally. But that is my biased opinion and my solid axle truck is currently down with wrecked steering.

Everything fails. What are you willing to fix?

 

[HenryJ]

For daily driving , ride , and handling the IFS is the only way to go. IFS is my choice for the desert terrain, and driving that I do. Higher speeds and float over the terrain. Check out the rally racers (baja 1000, Dakar, etc.) IFS is the design of choice there.
SFA has it's place too (mud, rockcrawling, etc.). I don't feel that there is any one suspension choice that is best for all uses , or terrains.

 

[downhill]

I have a Tacoma, so no perspective on the K2500. I will say that I like the IFS for moderate wheeling, and especially as a dual purpose vehicle. You can't lift them or run big tires so if you need that, a solid axle is better. You have considerably less unsprung weight which translates into a much less punishing ride. You have better handling characteristics on the road. I also prefer an IFS for deep snow driving. They present a higher center clearance which reduces drag without resorting to oversized tires. With a skid plate in front you essentially have a sled.

 

[Rot Box]

I like IFS personally. That said I hate torsion bars, idler arms, pitman arms, flimsy tie rods, underrated balljoints and designs that use only the shock to limit down travel...

 

[Larry]

I like “Coil” boinger front suspension too like Tacoma’s and late model GM and Dodge ½ ton 4x4’s have but not much of a fan of any torsion bar IFS...even old Toyota torsion bar IFS like my '90 Hilux had a terrible ride and off-road articulation. I have a 2001 GM HD 4x4 truck that I bought new with torsion bar front suspension and it is the worst riding truck I've ever owned. I really don't understand GM's hangup with torsion bars as they ride terrible and have nothing over a SFA Ford StupidDuty or Ram HD with a coil spring SFA. GM ditched torsion bars once on medium duty trucks in the 60's and went back to leaf springs, not sure why they didn't learn then. Rant off..... Not saying I am anti-IFS, I just really dislike torsion bars. The reality is even GM torsion bar suspension is sufficient for trail riding and back country explorations when running a conservative tire size. A modest lift with an open front diff with no more than 35’ tires and you would be fine.

 

[Revco]

Lots of sled pullers making several hundred horsepower over stock and gobs of torque are still running through stock GM IFS without issue. For daily driving and occaisional offroading the stock IFS is fine, but for harder rated trails and rock crawling, the IFS is no longer up to par and is more prone to failure due to the extreme forces applied to the axles, steering, and suspension components.

 

[FellowTraveler]

IFS and steering?

The GM IFS in the K2500/3500 up to 1999 are same units w/14 bolt IFS pattern and 9.25" ring gear they are very stout and don't suffer from bent or broken tie rods like the newer versions which have limited travel because tie rod attaches to end of center link and not the side as earlier versions do. Its a given most bad mouthing of gm ifs is because of steering issues, however when driven properly K2500/3500 9.25" IFS will last and last.

35" tires can be used w/o lift however cutouts and deeper gears sets are necessary.

I run Energy Suspension poly bushings the black ones w/graphite.

ARB locker in mine has saved the day many, many times but is a bull to steer when engaged.

Aftermarket tie rods from bullet proof suspension are a good upgrade but not really needed for most adventures.

Another mod I like is the snow plow bump stops (large diameter) trimmed for suspension travel that will keep your axle from coming out of the case if a new c-clip axle retainer is not installed when servicing ifs diff, a used c-clip is asking for trouble ask me how I know.

Finally, keep an eye on the rag joint hidden under the composite cover on steering box, I've been conned more than once to replace other steering components when only the rag joint was at fault.

 

[redthies]

As stated earlier, if you run 35s or less and maintain your suspension properly, you should not have any reliability issues. I have a serious love for the simplicity of a sas, but find myself looking at TTB F250s for my Cummins swap truck. The TTB is ifs of a sort, but not nearly as well thought out. I think a Dana 60 would likely replace the TTB as soon as any big money was required to maintain said TTB. That ought to take at least a few months!