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Are Some Differential Covers Better?


MikeO

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...or is it all about the look? I see different shapes, materials, and some "finned" I assume for temp. control. Any good reason to swap the old one out?

a.jpg
 

Chris

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With stock axles the only differential covers I would ever consider running are the Currie / Barnett diff covers which you can see here:
https://www.currieenterprises.com/js-hd30

They don't look pretty, but they provide the clearance you want.

The ARB diff covers and that fancy looking one you linked to above are very well known for causing interference issues with the track bar and such under full articulation.
 
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IPerkWVU

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With stock axles the only differential covers I would ever consider running are the Currie / Barnett diff covers which you can see here:
https://www.currieenterprises.com/js-hd30

They don't look pretty, but they provide the clearance you want.

The ARB diff covers and that fancy looking one you linked to above are very well known for causing interference issues with the track bar and such under full articulation.
Any issues with a rear ARB? Looks like I have plenty of space back there but haven't installed yet, picked one up for pennies on the dollar.
 

jjvw

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Any issues with a rear ARB? Looks like I have plenty of space back there but haven't installed yet, picked one up for pennies on the dollar.
A fat rear cover can hit the gas tank. It will depend on the pinion rotation, axle position and the amount of bump stop extension.
 

Mr. Bills

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The "Barnett" designed ramped front differential covers modify the stock cover in a way that there are no interference issues. The design is now offered by Currie for both the Dana 30 and Dana 44 front axles.

0000662_js-hd44-ramped-hd-diff-cover-for-dana-44-housings.jpg

https://www.currieenterprises.com/JS-HD44


I have diff covers from Solid Industries and no interference issues.

Diff-dana_44_large.jpg

https://www.solidaxle.com/productcart/pc/viewPrd.asp?idproduct=31&idcategory=0


As noted above, there are clearance issues with several brands. Research before you buy.

Note: Many aftermarket covers have high fill holes. This does not mean that they have a greater capacity. For example, Solid Industries recommends that one follow the manufacturer's capacity recommendations. Adding too much can and will cause hot gear oil to leak from the vent tube or blow past the seals. [Ask me how I know. ;)]
 

IPerkWVU

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A fat rear cover can hit the gas tank. It will depend on the pinion rotation, axle position and the amount of bump stop extension.
Good to know I'm really in no hurry to install it but I'll take a look at those interference points before I put it on. Savvy GT skid is also on the list so that clearance should help me out in that area.
 

jjvw

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Good to know I'm really in no hurry to install it but I'll take a look at those interference points before I put it on. Savvy GT skid is also on the list so that clearance should help me out in that area.
You'll have to remove the coils and run the axle as high as it will go in order to see how much room is there. The same is true of the front. Many covers require additional bump stop extension, which I consider a shame to limit your travel just for a diff cover.

Regarding the SOLID diff covers, I personally know someone who needed to cut out and re-plate the "D" in order to clear the front track bar. Search JF for the SOLI diff cover.
 

Mr. Bills

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. . . Regarding the SOLID diff covers, I personally know someone who needed to cut out and re-plate the "D" in order to clear the front track bar. Search JF for the SOLI diff cover.
You bring up a good point. Some track bars don't play nice with any aftermarket diff cover; others offer more clearance. Research both.
 
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jjvw

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You bring up a good point. Some track bars don't play nice with any aftermarket diff cover; others offer more clearance. Research both.
I recall the SOLI cover was paired with a ZJ tie rod, a JKS track bar, adjustable arms with about 1.5" of bump stop extension.
 

MallCrawlOnTons

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I know some folks will fight with me posting this here, for some of those interested in the tech, Gale Banks is doing a video serious on diff covers. He is mainly bitching about popular flat back covers for big axles, but the tech he talks about is interesting. Cover designs, oil capacity, fluid temp and etc.
It is not about Jeeps, rock crawlers, trial riders or web wheelers, but it’s interesting. Many of the things he talks about could be applicable to some of our diff cover selections.

first video of the series -
 

jjvw

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Not much to fight against. Banks suggests that the stock cover designs are very good at moving fluid around. The Barnett cover is a stock cover with clearance where it matters and armour where it matters.
 
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Mr. Bills

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General question re diff covers:

During the CJ/YJ era differential guards were widely in use. Aftermarket diff covers not so much. One of the most popular differential guards was the hockey mask style marketed by Mike Duncan at 4XDoctor in Burbank CA. I had one on the Dana 30 in my CJ-7, also the AMC 20 rear axle.

I don't see those on TJ's. Have they simply lost favor or is there some other reason? I would think that these would solve the issue of damaging the cover without raising the issue of interference with the tie rod or track bar.

diffguard_blue.jpg
 

jjvw

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General question re diff covers:

During the CJ/YJ era differential guards were widely in use. Aftermarket diff covers not so much. One of the most popular differential guards was the hockey mask style marketed by Mike Duncan at 4XDoctor in Burbank CA. I had one on the Dana 30 in my CJ-7, also the AMC 20 rear axle.

I don't see those on TJ's. Have they simply lost favor or is there some other reason? I would think that these would solve the issue of damaging the cover without raising the issue of interference with the tie rod or track bar.

View attachment 68648
My first thought is that those are as goofy looking as the Barnett is. (I mean that in the best way possible) Assuming they work well, the hockey mask probably fell into a niche market of functional products after the brodozer aesthetic took over the industry.
 

MallCrawlOnTons

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General question re diff covers:

During the CJ/YJ era differential guards were widely in use. Aftermarket diff covers not so much. One of the most popular differential guards was the hockey mask style marketed by Mike Duncan at 4XDoctor in Burbank CA. I had one on the Dana 30 in my CJ-7, also the AMC 20 rear axle.

I don't see those on TJ's. Have they simply lost favor or is there some other reason? I would think that these would solve the issue of damaging the cover without raising the issue of interference with the tie rod or track bar.

View attachment 68648
Ive always liked diff skids.
I personally like the warm industries one and the old school poison spyder customs one.

6C9103E3-0B58-4A6A-85E0-6F4295089347.jpeg


7C883A42-1062-4A04-ACCA-23F265223DDB.jpeg
 
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Boinked

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I would rather add a guard in front of the dif cover than change it. The manufacturer spent lots of time and money to design the cover to work for that axle. Do you think most aftermarket manufacturers spent that much money and that much resources into making sure every aspect of it works perfectly with that differential.

The only problem with factory differentials are sometimes the get hit and bent.
 
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jjvw

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I would rather add a guard in front of the dif cover than change it. The manufacturer spent lots of time and money to design the cover to work for that axle. Do you think most aftermarket manufacturers spent that much money and that much resources into making sure every aspect of it works perfectly with that differential.

The only problem with factory differentials are sometimes the get hit and bent.
You're also making an argument for the Barnett. :)