Transmission pans/differential covers

[TallyMax]

I've been looking at increasing fluid capacity for the engine, tranny and differential. I'm going to add the Amsoil dual bypass system for the power plant, but can't decide on the options for the tranny and rear end. I've read several posts that mentioned the Allison deep pan, but not much on the rear end choices. Here's the options I've found:
Tranny: Allison Deep Pan with the longer pickup
PML aluminum pan for the Allison
Diff: Mag-Hytec aluminum, magnetic dipstick,
PML aluminum cover with magnetic drain.
The PML site is yourcovers.com. Looks to be good quality, but can't find anyone with any dealings with this group. Anybody out there have an opinion??? :cool:

[SoCalDMAX]

TallyMax,

That's the first I've heard of PML. I went over and took a look at their pans.

The Allison pan looks kinda nice. The Allison gasket is awesome, so sealing to the pan should be fine. The 2 cons that come to mind is the Allison tranny doesn't overheat, so for people in cold climates the extra heat rejection of a finned aluminum cover might lengthen the tranny warmup time. The other con is I don't know how well a cast aluminum pan would hold up if bashed on a rock with the force of a truck on top of it. The Allison deep sump is steel and might deform but probably won't crack. It's not too expensive and I painted mine, it looks pretty good.

The diff cover has an unusual fin pattern on it, probably to differentiate from Mag-hytech. It only holds 1 extra qt over stock, the Mag-Hytech holds an extra 4 qts. It also doesn't use a gasket or o-ring, just sealant. I don't care for that method.

I don't know anything about the quality of their castings, but they certainly do look nice in the pictures. What kind of prices are they talking? I had to gulp once when I paid for the mag-hytech, but when it arrived, I was astonished at the quality of all of the machine work, including the premium fasters. Just MHO.

Regards, Steve

[TallyMax]

SoCalDMAX,
The PML prices are app $200 for the tranny pan and $150 for the differential cover. I'm with you on a couple of points: the Allison pan is inexpensive and I'm sure more durable, the Mag-Hytec seems to have better quality and a better gasket system, plus it has a magnetized dip stick. A couple questions on the Mag-Hytec: does it increase the capacity from 4qts to 8qts? and I seem to have read something about a vent problem on the top of the cover, that with our rear end it throws oil out of the vent? The OEM cover doesn't have a vent that I can tell, does the Mag-Hytec? Can't remember what site I read this on or for sure if our model is the one affected. On the heat situation for the Allison, we don't get below 20 degrees very often, but do get near 100 pretty regular, so I'd rather be safe than sorry if I have to tote a big load in this heat. Maybe I'm overplaying this, but I would like to keep this truck a long time. Heck it's gonna take a long time to pay for it! Thanks! :D

[hjd3021]

I have the Mag-Htek cover on my truck. Capacity was just shy of 8 quarts to bring the fluid up to the normal range on the stick. I have not had any problems with venting fluid so I'm not sure what this is referring to. The cover has several holes in it for temperature transducer, drains, etc. but all are very leak tight.

[SoCalDMAX]

TallyMax,

Neither the factory diff cover nor the M-H cover have a vent, the vent is built into the axle tube or pumpkin itself. The vent on mine had a really long tube that went up to the top of the fuel tank (unless that was something else venting into the pumpkin, which I doubt). I've never had any venting issues at all, not a drop.

The M-H cover increases capacity from 3.8qt (4 in my opinion) to almost 8qts. There is a range on the knurled dipstick just like the engine oil dipstick. I'm using Amsoil gear lube and I've heard talk of Amsoil weaping out of oil pan gaskets, but I'm not having any weaping or leaks of any sort.

Regards, Steve

[Jim Dandy]

Did my first pull with my Mag Hytec Diff cover last night. Was only 30 miles and at speeds under 60 MPH. It did include some hills though. Max rear end temp I saw was 150 F. Max unloaded highway temp I've seen so far is 120 F.

I like the cover. Good quality.

[SoCalDieselNewbie]

Anybody have the part #s for the Allison Deep Pan and Long Pickup? Also aprroximate cost?

By the way, Newbie gots the inside info on a new player in the T-1000 Deep Sump arena. Me thinks that you'll like the product based upon reviews of his other product. Look for it around Dec '02 or Jan '03. :D

[77TransAm]

The deep pan is p/n 29536522.
The deep suction filter is p/n 29537966.

[SoCalDieselNewbie]

Trans AM,

You are the man... Thanks!

[mdrag]

Topic moved to 2500HD/3500 HD Trucks & Drivetrain Forum.