Iron 7.25" Front Differential Vs. Aluminum ?

killian96ss · Post by **killian96ss** » Wed Mar 02, 2005 12:07 pm

Is the iron 7.25" front differential that much stronger than our aluminum one? Is this a worthwhile upgrade or just a waste of time and $? I was just reading an article in Off Road Adventures that the ZR2's have iron front diffs. instead of the aluminum one we have, and they mention that they are a little bit stronger.

??

Steve

Retep · Post by **Retep** » Wed Mar 02, 2005 1:37 pm

Every ZR2 I have seen has the same aluminum front diff we do.

killian96ss · Post by **killian96ss** » Wed Mar 02, 2005 2:28 pm

Retep wrote:Every ZR2 I have seen has the same aluminum front diff we do.

Does this mean the info in the Jim Allens Gearhead tech section of the March 05 O.R.A. is incorrect?

Here is the exact quote referring to a 2002 S10 ZR2. " The weakest link is in the front end. The ZR2's have an enhanced front diff (iron housing instead of aluminum), but it's still fairly weak ". Maybe the newer ZR2's have different housings? I have read somewhere that the 04-05 ZR2 Blazers have an upgraded front diff with stronger gears.

Or maybe O.R.A's tech editor doesn't really know what he's talking about.

Steve

Retep · Post by **Retep** » Thu Mar 03, 2005 6:10 am

All I know is that I have seen aluminum front diffs on ZR2's which look just like ours. This might be a good question to pose to the ZR2.com people and see what most of them have.

killian96ss · Post by **killian96ss** » Thu Mar 03, 2005 9:29 am

Retep wrote:This might be a good question to post to the ZR2.com people and see what most of them have.

Good idea, I will give that a try. I thought the Typhoon's and Cyclones were the only ones with iron front diffs.

Steve

Rusty · Post by **Rusty** » Thu Mar 03, 2005 4:06 pm

Only thing I have heard, and I think it was on S10Extremist, is the aluminum cases are prone to tearing off their upper mounting tabs but the iron cases don't. Everything else is the same.

killian96ss · Post by **killian96ss** » Thu Mar 03, 2005 7:05 pm

Rusty wrote:Only thing I have heard, and I think it was on S10Extremist, is the aluminum cases are prone to tearing off their upper mounting tabs but the iron cases don't. Everything else is the same.

I wonder what the most common failures are for the front diff.? I know all of it's weak, but what is broken most often?

Steve

Rusty · Post by **Rusty** » Thu Mar 03, 2005 7:50 pm

killian96ss wrote:
Rusty wrote:Only thing I have heard, and I think it was on S10Extremist, is the aluminum cases are prone to tearing off their upper mounting tabs but the iron cases don't. Everything else is the same.
I wonder what the most common failures are for the front diff.? I know all of it's weak, but what is broken most often?

Steve

I pulled the front diff out of the first S-10 Blazer I had and looked it over. The thing seemed so small I thought it looked like it should be in a riding lawnmower, not a truck. I could see where the mounting tabs could break off but the whole thing just seemed weak to look at it. I've heard if you throw enough torque at it, the whole thing just kinda explodes. I know there is a guy that swapped the 8.25" front diff from a full sized into a ZR2 but I haven't been able to find out how he did it. Lot of custom parts and money I guess.

killian96ss · Post by **killian96ss** » Fri Mar 04, 2005 8:34 am

Rusty wrote:I know there is a guy that swapped the 8.25" front diff from a full sized into a ZR2 but I haven't been able to find out how he did it. Lot of custom parts and money I guess.

This would be a good upgrade.

I wonder how hard it is to do?

It probably is expensive though since it's not a very popular mod.

Steve

Rusty · Post by **Rusty** » Fri Mar 04, 2005 12:14 pm

killian96ss wrote:
Rusty wrote:I know there is a guy that swapped the 8.25" front diff from a full sized into a ZR2 but I haven't been able to find out how he did it. Lot of custom parts and money I guess.
This would be a good upgrade. I wonder how hard it is to do? It probably is expensive though since it's not a very popular mod.

Steve

Here's the guys website - it's all I have on it.
http://www.zr2usa.com/members.php?id=3

Looks like he's got some serious cash invested in the truck. A 427ci LS1? Yep, big bucks!

killian96ss · Post by **killian96ss** » Fri Mar 04, 2005 7:10 pm

Rusty wrote:Looks like he's got some serious cash invested in the truck. A 427ci LS1? Yep, big bucks!

Now that's a cool toy!

I wonder what it's like to drive an S10 with 510 hp.?

Steve

Rusty · Post by **Rusty** » Sat Mar 05, 2005 5:24 am

killian96ss wrote:I wonder what it's like to drive an S10 with 510 hp.?

Steve

killian96ss · Post by **killian96ss** » Wed Mar 30, 2005 1:28 pm

After posting this ? @ ZR2.com I have learned that the older ZR2's did have iron front cases instead of aluminum. I think the switch to aluminum was made around 96-97. The ZR2's also have hardened front ring and pinion gears. I wonder how much stronger an iron case and the hardened gears would be over our stock setup? I would rather break halfshafts than the differential itself if possible.

Steve

Rusty · Post by **Rusty** » Wed Mar 30, 2005 2:52 pm

killian96ss wrote:After posting this ? @ ZR2.com I have learned that the older ZR2's did have iron front cases instead of aluminum. I think the switch to aluminum was made around 96-97. The ZR2's also have hardened front ring and pinion gears. I wonder how much stronger an iron case and the hardened gears would be over our stock setup? I would rather break halfshafts than the differential itself if possible.

Steve

Ironically, I just stumbled onto the GM part number for the iron case. It's apparently still available from GM (in fact GM parts direct listed it too). Seems I no sooner found it that I misplaced the link!

I'll hunt around and see if I can find it again. I'd be interested in one myself since I canned the SFA idea on my Blazer.