Here is a question that got me the other day..

Companies out there (ORU Burbank for one) offer the IFS to Solid Front Axle Conversion, an expensive little option. I had a customer pop this question on me. Would a Solid Front Axle conversion increase or decrease the amount of weight in the front. Not knowing how heavy all the suspension components on a IFS truck would be, I was stuck on this question. For weight comparison on the solid front axle, lets say the replacement axle is a Dana 60 with an crossover type steering. Anyone want to take a stab at this one?


- Mark

I think the D60 weighs quite a bit more than the IFS. Just my .02$

IMO total front end weight would be about the same give or take 50lbs. Unsprung weight would increase by a far amount,because now the whole axle has to move vs. just the outer hubs and control arms. Not being a smarta$$,but why would this make a difference to your customer. Weight would be my last concern about the swap.

Yes I would guess on SFA adding at least 100lbs probably more.

Yup, front end weight would increase some, but it is all unsprung weight. The actual weight carried by the new front springs would be less than the torsion bars carry on a stock truck.

Well i can help ya out alot here... This is my 1990 GMC it is SAS'ed and 1-ton'd..
D60 Kingpin Front and 14-bolt FF rear!!!

A Kingpin D60 complete with axle shafts and ring gear an dcalipers etc... weighs in at about 530 lbs. if I remember correctly... Older GM IFS isnt really that heavy since its aluminum differential.. I can carrier my old 8.25" Diff. in one arm and can pick up my old lower control arms and knuckles like a shoulder shrug without struggling..

IMO: -It would probable as far as the axle goes way about 75-100 lbs. more, but like some others said this is UNSPRUNG WEIGHT not carried by the springs. Tires and Rims are also UNSPRUNG!!!

I say go for it... If ya have any ???'s let me know!!! I have another Hp D60 that i plan on sticking under my D-max when tis TOWING DUTIES are no longer needed!!

BIG

http://memimage.cardomain.net/member_images/8/web/332000-332999/332119_219_full.jpg

I never got to the point of his question..although he had alot of concerns about lowering his gas mileage when we were disscussing lifts and such so I would only imagine that being the purpose of his question. That or hes quite a diesel speed fanatic, like all of us here, and Im sure it was relative to what it would do to his performance - times, speed, etc..)

Why people spend $5000-$10,000 on a lift and worry about a couple MPG(s) I dont know, but I feel him on the performance issue. Lighting up the load would cause accelerated times, not being aware of how this would effect the track (weight)..I could'nt give him a straight answer. Suggestions?

I'd imagine (exluding the fact of bigger tires) a Solid Front Axle (w/ Unsprung weight) it would lower MPG..and worse with 35x12.50 say. Asides the fact of his asking, I was also courious on weight differences as well. I own a 77 K5 with a 383..and weight differences between my trucks front end and the 77s, it was always a point of conversion between IFS and SFA's. I was just un-aware on how much weight(metal) consists of a IFS.

Thanks guys, always knowledgable once again!

- Mark