Mag-hytec Differential Cover

Paul58 · October 31, 2007

I just orderd a Mag-Hytec Differential Cover for my truck. It claims beeter performance for the rear end by helping it run cooler. With towing a 7000 lbs Travel Trailer, I figure it wouldn't hurt.

They claim it hold 4 quarts of gear oil and has a magnetic dipstick. When I ordered it said the size for my truck (GM #10-8.5) also fit the 2500. So, I'm wondering if with the addition of this high capacity differential cover and the 3000 lbs SuperSprings, have I effectively increase the tow/hauling capacity of my truck to that of a 3/4 ton pick-up?

MS3DALE · October 31, 2007

If its the 10-bolt,8.625" rear-end you have that cover can't fit the 2500,Those have at least the 14-bolt,9.5" rear-end in them,and most have the 10.5" or 11.5" rear-end.

Even the 1/2-tons with the 6-liter "VMax" have the 14-bolt,9.5" rear-end.

Gozer · October 31, 2007

How much did you get it for and from where?

I've been thinking of one of these also for towing, but I figured I'd wait until I change my fluid. Not even sure when this needs to be done with the synthetic gear oil, and I don't recall a change interval in owner's manual. I'm thinking around 30k miles.

Krambo · October 31, 2007

Nice looking piece however if you really wanted to beef up the GM 10 bolt, you should replace the bearing cap bolts with studs and get a cover that actually places additional center load on the bearing caps. I suggest the TA girdle.

Here is what mine looks like:

And here is a shot of the studs vs. the stock bearing cap bolts:

Bearing cap stud installed (no nut on) on the passenger side lower location:

And the stud fully installed with the nut. These are ARP hardware and is top notch. Note the ARP stamp in the nut?

\

This is why a "girdle" is better than just a larger capacity cover. See the load bolts that supply additional support for the bearing caps?

Torque down the load bolts once the cover is installed:

Final look!

I did a complete "How-2" on beefing up the GM 10 bolt over at SilveradoSS.com. Check it out!

My How-2 on beefing up the GM 10 bolt link!!!

Paul58 · October 31, 2007

How much did you get it for and from where?

I've been thinking of one of these also for towing, but I figured I'd wait until I change my fluid. Not even sure when this needs to be done with the synthetic gear oil, and I don't recall a change interval in owner's manual. I'm thinking around 30k miles.

I got it from Grimm Performance for $225.99 shipped. It was the best price I could find on the net.

Paul58 · October 31, 2007

krambo,

I'll have to check out your pics and How-To when I get home, I can only view text at work. I based the comment about the 2500 on what I read on the Mag-Hytec web site under applications: It says 99 to present 1500, 2500, and SUV! Pretty broad, so maybe there was a 2500 in there someplace with the 10-8.5 rear end!

In any case, I'm interested in the cooling aspects of this mod being as most of the hard work the truck is subjected to is towing our Travel Trailer. It does not put excessive weight on the rear axle like a 5th wheel or goose neck trailer, and the toungue weight of the trailer is under 700 lbs! I am looking forward to checking our your pics and how-to though!

silverad03 · October 31, 2007

So, I'm wondering if with the addition of this high capacity differential cover and the 3000 lbs SuperSprings, have I effectively increase the tow/hauling capacity of my truck to that of a 3/4 ton pick-up?

Unfortunately, no. If you have a 1/2-ton pickup, then your trailer is still connected to a 1/2-ton frame, which isn't as big or beefy as a 3/4-ton frame. The springs and the trailer hitch all transmit forces against the frame, which is there to hold everything in place. The springs and high-capacity differential cover help the truck handle the weight better, but your towing capacity is still limited by the weakest link in the chain - which is your frame in this case (if not your hitch). The same goes for the powertrain and driveline - the extra stress of hauling/pulling loads in excess of the rated towing capacity could potentially have a dramatic effect on the durability of those components.

Paul58 · October 31, 2007

So, I'm wondering if with the addition of this high capacity differential cover and the 3000 lbs SuperSprings, have I effectively increase the tow/hauling capacity of my truck to that of a 3/4 ton pick-up?

Unfortunately, no. If you have a 1/2-ton pickup, then your trailer is still connected to a 1/2-ton frame, which isn't as big or beefy as a 3/4-ton frame. The springs and the trailer hitch all transmit forces against the frame, which is there to hold everything in place. The springs and high-capacity differential cover help the truck handle the weight better, but your towing capacity is still limited by the weakest link in the chain - which is your frame in this case (if not your hitch). The same goes for the powertrain and driveline - the extra stress of hauling/pulling loads in excess of the rated towing capacity could potentially have a dramatic effect on the durability of those components.

Thanks for the feedback! I don't plan on exceeding the capacity of my truck, was just curious if there was more to a 3/4 ton than just suspension parts! The mods I've made are more to give more of a margin of safety and reliability to my truck. My current towing capacity is 7700 lbs and our trailer fully loaded is just under 7000 lbs, I just want to ensure it handles safely and the hard working parts (drive line) last a long time!

pm26 · October 31, 2007

I agree with everything in the post above. One benefit of this differential cover is keeping the rear end oil temperature down because aluminum dissipates heat much better than steel. But, as mentioned, a 1/2 ton picup is a light duty truck and should never be used as a 2500 or 3500 truck. You are severely limited by the light duty rear axle, lighter duty transmission, springs, and the frame of the vehicle. Also, the 5.3 liter V8 power is marginal for a 7,000 lbs trailer, especially in mountainous areas.

In my opinion, the max practical towing capacity of your truck is the rated capacity minus 25%. this is the max weight I would tow with my truck to avoid excessive tear and wear.

Paul58 · October 31, 2007

I agree with everything in the post above. One benefit of this differential cover is keeping the rear end oil temperature down because aluminum dissipates heat much better than steel. But, as mentioned, a 1/2 ton picup is a light duty truck and should never be used as a 2500 or 3500 truck. You are severely limited by the light duty rear axle, lighter duty transmission, springs, and the frame of the vehicle. Also, the 5.3 liter V8 power is marginal for a 7,000 lbs trailer, especially in mountainous areas.

In my opinion, the max practical towing capacity of your truck is the rated capacity minus 25%. this is the max weight I would tow with my truck to avoid excessive tear and wear.

Well, it did pretty good towing 7000 lbs over the TN Mountains, it maintained a steady 50 mph and the tranny and coolant temps never broke 200 degrees! That was using tow/haul mode in 3rd gear, and I don't really feel I was pushing it at all! I could have easily wound it out and probably could have taken the grades at 65-70 mph, but that would have been abuse!

Zembonez · October 31, 2007

Well, it did pretty good towing 7000 lbs over the TN Mountains, it maintained a steady 50 mph and the tranny and coolant temps never broke 200 degrees! That was using tow/haul mode in 3rd gear, and I don't really feel I was pushing it at all! I could have easily wound it out and probably could have taken the grades at 65-70 mph, but that would have been abuse!

Common sense goes a long way when you are towing. Sounds like you were using yours well.

I believe a lot depends on how much you use your truck to tow. If you tow a lot, I think a 2500 is in order for that 7000lb trailer for sure. If you only do it occasionally (and carefully as you have described) I don't think you'll see much harm.

Just my .02 worth.

Paul58 · October 31, 2007

Well, it did pretty good towing 7000 lbs over the TN Mountains, it maintained a steady 50 mph and the tranny and coolant temps never broke 200 degrees! That was using tow/haul mode in 3rd gear, and I don't really feel I was pushing it at all! I could have easily wound it out and probably could have taken the grades at 65-70 mph, but that would have been abuse!

Common sense goes a long way when you are towing. Sounds like you were using yours well.

I believe a lot depends on how much you use your truck to tow. If you tow a lot, I think a 2500 is in order for that 7000lb trailer for sure. If you only do it occasionally (and carefully as you have described) I don't think you'll see much harm.

Just my .02 worth.

We tow mainly for weekend get-aways, and rarely more than 2 hours from home. I'm moving to Atlanta in Dec, so we hauled it down there 2 weeks ago as to not end up doing it in snow! That was a 9 hour trip, and probably the longest we'll do with the current truck/trailer combo! The next truck will be a 2500 with a diesel, and we'll probably upgrade to a 5th wheel around the same time.

My stock rear differential cover is already exhibiting a good bit of surface rust, and I can't help but think heat generated by towing is a contributing factor. So, if a larger capacity cover with heat dissipating fins and a good synthetic gear oil with keep things cooler, all the better, and the longer it will last! You know, the ole ounce of prevention...

C & A s Dad · November 1, 2007

I have been considering adding a higher capacity finned allum cover to my Yuk XL as well. I have found one from yourcovers.com that will add about 1/2 qt capacity to my diff while still fitting my Yuk XL. GM SUVs have a track bar that runs just behind the diff cover and pick ups do not have this bar. Many companies do not offer a cover that will clear this bar. I will have to check out this company that you are using.

Paul58 · November 1, 2007

I have been considering adding a higher capacity finned allum cover to my Yuk XL as well. I have found one from yourcovers.com that will add about 1/2 qt capacity to my diff while still fitting my Yuk XL. GM SUVs have a track bar that runs just behind the diff cover and pick ups do not have this bar. Many companies do not offer a cover that will clear this bar. I will have to check out this company that you are using.

Trey,

I don't think they make one that accomodates the rear sway bar. When I reviewed the installation instructions it mentioned using shimms and spacers to relocate the sway bar to add the needed clearance for the deeper cover.

cmoore74 · November 1, 2007

How much did you get it for and from where?

I've been thinking of one of these also for towing, but I figured I'd wait until I change my fluid. Not even sure when this needs to be done with the synthetic gear oil, and I don't recall a change interval in owner's manual. I'm thinking around 30k miles.

My '06 owners manual recommends changing the fluid after the first 500 miles of towing. I don't recall any mention of an interval after that.

Amsoil suggests 25k miles for severe service and 50k miles for normal service.

My guess for a truck that occasionaly tows would probably be somewhere in between 25k and 50k.