What Flavor of RTV Silicon?

[Shelby Griggs]

Getting ready to dump the diffs. What RTV sealant should I use, black, gray, bronze, other????

TIA

Shelby

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2001. 5 2500 QC LB 4WD, ETH (Built 09-10-00), DEE, 3. 54 gears, Laramie SLT, Camper Special, Trailer Tow, Travel Convenience Group, Power Driver Seat, Alarm System, Remote Keyless Entry, Fog Lamps, Cab Clearance Lamps, HD Transfer Case, Bright White with a Gray Interior. Built 09-15-00, took delivery on 10-06-00, 12310 miles as of 05-01-01. Custom aluminum work body / flat bed. Coming soon: E-Brake and gauges.

 

[EMDDIESEL]

Cant remember the name off hand but its blue and its made by Permatex. Hope that helps

 

[illflem]

Shelby, I don't think it matters much for the diffs, black matches the best. I personally use the red Permatex flange and gasket seal, works just fine.

 

[Alan Reagan]

Ultra Copper for the differentials. Great heat and sealing characteristics. Combines the best of the best RTVs. There was no indication of set time when I changed mine so I put the cover on and let it set about 3 hours before filling. You may remember, I changed to synthetics in the diff about two months ago, I noticed a couple of days later that I had a leak. By the time I got home that evening, the black sealer I used had almost completely disintegrated. The Ultra Copper has worked good.

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2001 HO 6 spd 2500, 4. 10 LSD, Towing Package, Electric Brakes, SPA EGT/Boost Gauges, Fog Lights, Real Backup Lights, Molded Running Boards, Lucerix X Mount Heated/Power Mirrors

 

[Paul Somers]

You will find when you get the cover off that the original sealant was grey. I used ultra grey and it has held up with no leaks.
PS: Latest issue TDR has article on replacing rear fluid.

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Northport,AL. 1999 2500 quad cab, driftwood, 5 speed ISB. Boost and Pyro gauges. Line-x.
Amateur extra W4XH

 

[Vaman]

I used the permatex blue for oil. The color is a little strange but no leaks.

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98. 5 2500, 24v, 5 speed, QC, 4x4, 4. 10 LSD, short bed, Line-X liner, tow package, camper suspension, Westin nerfs, camper shell, TST PowerMax Competition, 275 RVs, Psychotty air, HX-40, 4" straight pipe exhaust, ProComp A/T 305/70/R16s, EGT/Boost pillar gauges, Grover air horns... Love my Cummins, no love for Dodge

 

[TXRam]

Well, I used the Permatex Black high temp stuff - about a month ago and zero leaks. And like someone else stated - it matches.

 

[LSMITH]

Grey was on it when I got it, so I put grey back on it. You will have a lot of respect for the grey when you take the cover off, and it is holding the synthetics fine with no leaks.

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99 2500 QC 4X4 AUTO SB 24V LARAMIE SLT 3. 5 LSD 285-75-16'S SPA Boost/EGT Rancho 9000's Everything but leather NRA Member Great Lakes TDR Member

 

[PUFF00]

The information that came with my Mag-Hytec suggested using Ultra Black to seal irregularities that can't be filed smooth, and the sections with the numbers. I figure those people should know what they are talking about. I really have no clue as to the differences between the various types, so I just followed their instructions and used the UB.

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2001. 5 3500 QC 4X4 6-speed HO 3. 55 black
1998 Jeep TJ black http://www.nm4w.org/members/puffer.htm

 

[Shelby Griggs]

Thanks for all of the tips. It is back on with Permatex Ultra Blue. Tried for the Gray, but the tube I got was already cured. Went back @ closing time (why does it always work out like that) to find I must have bought the last tube of Gray on the first trip. Since it was 21:00 hours, and I wanted to seal it up and be curing overnight, I got the Ultra Blue. Hardest part was getting that sucker back in place without getting Ultra Blue on everything in sight. Was not entirely successful, but I think enough remained on the proper side of the cover to create a seal. I got squeeze out all the way around. Will see tomorrow, when the Amsoil 2000 75-90 goes back in.

Shelby

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2001. 5 2500 QC LB 4WD, ETH (Built 09-10-00), DEE, 3. 54 gears, Laramie SLT, Camper Special, Trailer Tow, Travel Convenience Group, Power Driver Seat, Alarm System, Remote Keyless Entry, Fog Lamps, Cab Clearance Lamps, HD Transfer Case, Bright White with a Gray Interior. Built 09-15-00, took delivery on 10-06-00, 12310 miles as of 05-01-01. Custom aluminum work body / flat bed. Coming soon: E-Brake and gauges.

 

[Lurch]

I'm sure I'll probably get blasted for this, but I've never waited for the cure. Water pumps, differentials, thermostats, etc. . Permatex Blue, tighten the bolts, fill it up and go. Occasional leak on a water pump but percentage wise I've allways made out real well. How many mechanics park a car overnight to cure silicone? None. If it doesn't leak right away it's not going to.

Just my opinion.
Eric

 

[illflem]

I do it much the same way, usually wait only five minutes, have never had a leak.

 

[hammong]

The difference between the various colors of RTV has to do with the varying degrees of pliability and heat resistance after curing. I'm pretty sure the temperature range goes something like this: Black, Grey, Blue, Red, Copper. For "low temperature" applications like differential covers, the black will suit just fine. Black also remains the MOST pliable after curing, which some could translate into providing a better seal in cases where fitment isn't exact or parts are subject to flex. The Red and Copper grades are suitable for providing exhaust gaskets.

Greg


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Y2K Dodge Cummins QC 2500 SLT Laramie 4x4 Long Bed, 4. 10/Auto, Forest Green/Driftwood, 265x75R16 Michelin LTX, 6 speaker CD, Camper/Tow/Plow Packages, Westin Black Nerfs, Mopar bedliner, Ultra bright diamondplate toolbox, K&N Filtercharger. Autometer EGT and Boost gauges with 2-gauge pillar coming soon!

http://www.rints.com/hammond for photos!

 

[Mick2500]

Shelby,
Ya' done good. #ad
The Ultra blue has
aluminum particles in it and seals the best when using it around oil. You 'should' be able to remove any excess with an Xacto knife.
If it's smeared, use a rough rag and a little lighter fluid.

Mick