Is there any real strength differences between the V6 and 4cyl versions of the 7.5 IFS front diff used from 86 to 95?
As far as I understand, the only difference is the size of the carrier bearings and the housing the outside race presses into. Are there any other differences that I am missing?

Thanks

ccannon222

 

the 4/6cyl 7.5" diffs are the same. The ADD diffs are slightly different in that the output shafts have needle bearings as opposed to none in the non-add. Someone correct me if I'm wrong.

 

Thanks for the reply. I understand the differences in ADD and non ADD. I’ve converted one ADD to standard for my father so he could have 4.88 gears.
I thought there was no difference also, however when I started looking into master install kits for my brother, I noticed that there are two different kits. I also found a thread where ZUK stated that the outside diameter of the carrier bearings were different. V6 being larger.
What I haven’t been able to find is if there are any other differences and if there is any real world strength advantage with the V6 over the 4cyl versions. Between my father, brother and myself, we have several 7.5 IFS diffs laying around and we not been keeping track what they came out of. If the V6 case is different, then I really need to start labeling them.

ccannon222

 

Thats rear diffs

 

Then why does numerous websites including Marlin Crawler and Randy’s Ring & Pinion list different install kits for V6 and 4cyl IFS front?

Thanks

ccannon222

http://www.marlincrawler.com/htm/diff/pickup_diff.htm

When putting together your differential you will want a top quality setup kit to ensure long life. Yukon gear kits feature high quality bearings and seals. Kits also include a factory crush sleeve, pinion nut, and gear pattern paint.
Genuine Japanese KOYO bearings!

MC-14650, 4-Cyl Setup Kit, $105
MC-14651, V6 & High Pinion Setup Kit, $149
MC-14652, IFS 4Cyl Front Setup Kit, $141
MC-14653, IFS V6 Front Setup Kit, $167

 

Well, find out if the difference for the kits between the V6 and 4cyl aren't specifically related to V6 units that came with 4.88's from factory. Those are different, for sure.

And, regardless of any differences, even Zuk has told me that the strength differences are debatable in a real world application between the two. This is, of course, if you are comparing OEM equipment to OEM equipment.

 

The V6 diff has a larger OD on the carrier bearings.

I wouldn't really give it much in the strength department, since its not the carrier bearings that make the 7.5" diff weak.

I wouldn't sweat it. You'll break a v6 diff just as fast as a 4cyl.

 

That’s what I figured about the strength difference.
It just doesn’t make sense why Toyota would go through all of the trouble (cost) to produce two different diff housings for V6 and 4cyl if there isn’t much strength different. I know the R&P is the week spot along with the CV joints, but larger bearings can help reduce gear deflection which contributes to broken R&P

Main thing I need to do is mark which diffs came out of a 4cyl and a V6 so if we re-gear them we order the correct install kit.

Thanks

ccannon222

 

It is odd, I agree.

Let me get this straight. The only difference is the bearings on the IFS V6 vs 4cyl front diffs?

Does this mean a carrier replacement like a Truetrac or ARB would be the same for both, but with different bearings?

 

I installed a V-6 front diff ADD and had to change the housing from a non ADD and installed a oil seal that wasnt there on the ADD.After everything is put together I encountered no problems on the axle and front suspension mounting.

 

ARB yes, Trutrac, not sure...

Trutrack lists different part numbers for v6 and 4cyl. it may have a different ID on the bearing as well.

I am running a v6 ARB in my truck. I had to get the smaller bearings, however.