Topic: 30 spline output question

[dirtybird]

Changed oil and rear output seal today on my marlin dualcases with 30 spline outputs and now have a bad vibration? Any help? From new these cases leaked all over but I would just top off every oil change. Was headed to pismo for this weekend figured I would drop oil (again) and change rear seal as it was leaking.  Cases have 9000 miles and all street driven. Noticed flange seems to fit loosely on output? Help please. Really dont want to take off and send back

[BigMike]

Hello dirtybird,

Thank you for your post on this. I was about the make the same comment regarding a loose flange. Be sure to get the flange nut torqued down properly to 90 ft-lbs and double stake it. Loose flanges is the #1 cause of "t/case" vibrations.

As for t/case leaks, you should know this is not normal. In fact oil leaks anywhere on any vehicle is not normal. There are a few incorrect things people do during housing reassembly such as using low grade silicone (such as blue/orange/red aftermarket silicones), combine silicone with paper gaskets, applying silicone to an oily surface, or using a chisel to separate housings during disassembly and then forgetting to hand-file all mating surfaces to prevent leaks before reassembly. All of these practices are not recommended by the factory service manual and for good reason.

Question: What rear output seal are you using? We supply a special Oversized EcoSeal rear output seal that is available separately. A stock output seal will not work with our huge output shaft.

BigMike

[dirtybird [OP]]

I purchased this dual case with comp gears and 30 spline outputs assembled from you guys complete. I installed and filled with redline synthetic oil. Never drove it as I had it on the lift and was still building the rest of the truck. When I showed up the next day just sitting there oil was leaking from everywhere !! I spoke with you guys about it and you guys wanted me to take them out and send them back but I was too anxious to drive my new truck. So I tried to work out having Yotamasters do the work and you guys cover it as they are local that didnt happen. Both you guys and Eric at Yotamasters thought switching to conventional gear oil would cure the problem, it didnt. So every oil change (3000) miles I had Yotamasters top off transfercases with oil. Well wanting to go to pismo for a yota get together figured time to change oil going to go back to synthetic ( amsoil) as it was a long drive to pismo. I purchased new set of your marlin output seals and replaced the rear. I put the nut back in the same position and now comes the vibration? It's only been street driven so far as I havent had time to take it out. Also when I took the driveshaft off oil came pouring out? Between splines of output and output flange so when swapping seals i put grey silicone on flange splines on reassembly. That was the only thing different I did as there was no silicone there prior. My rig has 10,000 miles now. Everything is new and all my parts are from you. You can look up my name in your files and see what I've purchased. My whole rig is marlin !!!! Lol other than engine and all pro suspension. Any help would be appreciated. Oh name is Javier Maisterra

[TheChewMaster]

You gotta use a torque wrench. Using the original steak position will not be the same as 90lbs

[dirtybird [OP]]

Thanks will try that next when im sure of torque spec. In marlins how to directions I read 110 ft lbs and mike responded 90 ? So when I hear from mike again I will try that.  Thanks for all the help

[dirtybird [OP]]

Also want to purchase new nuts for the outputs? Dont see them anywhere in the store to buy? Thanks

[BigMike]

Hello dirtybird,

Yes sorry 110 ft-lbs is correct (90 ft-lbs is for a factory output). You really need to get that case sent in to us to fix the leak. That is no good.

As for the parts, we don't list them individually on our website but if you give us a call we would be more than happy to get you a new output nut!

Thanks
Mike

[dirtybird [OP]]

Much appreciated Mike, I will make that call tomorrow. As for sending the cases in. Let me clean everything off real good, redo the output and nut to torque spec and see what happens. If I still have issues I will give you a call and we can discuss sending them in.  Thanks for all your help and hope to see and meet you guys someday on the trails!!!

[BigMike]

I forgot to comment on the splines of the output and flange. It is good you applied sealant (silicone) here because gear oil can make its way through the splines and leak right through the center of the flange (I've removed many a drive shaft only to get oil dumped on my face). A few things to note because this is sometimes tricky:

You really need to degrease the splines on both the output and the flange as best as possible. Oil and solvent repel each other and its often difficult to get the oil off the output due to how limited of working space you have, and of course the uneven surfaces of the splines. Don't worry if you get brake cleaner inside the t/case, such a small amount won't damage anything. I'd give the output a good shot of brake cleaner and use a clean shop towel or clean rag and really try my best to get that output clean & dry. Do the same to the flange. Then apply silicone to both the splines of the output itself and the flange, then install the flange ... and then also -- and here is what most people don't do -- clean/degrease one side of the flange washer and apply silicone to it as well on it's flange facing side before sliding it onto the output and before following it with the flange nut.

The last point would be give a final defense in catching any leak caused by any remaining oil that you just couldn't clean off the output splines. Just as an extra step towards a dry driveway

Regarding the mileage on your cases, 10,000 may be outside of our warranty but it's good you have record of it leaking. I am not the one to make the call on how this will be warrantied but I think it's a good idea to give us a call just to follow up on it. At the most I could see us charging a small fee to open up, inspect everything and reseal it all up. It may be in your interest to have things inspected and checked out anyway!

Regards,
BigMike

[dirtybird [OP]]

Ok thanks mike, and on that important note of a washer? I don't have a washer between the nut and flange?

[BigMike]

Ha, sorry, yes you are correct, I was thinking of a stock setup. We supply a huge flanged-type nut that doesn't use a washer. So please degrease and apply silicone to the flanged side of the nut (the side that comes in contact with the flange) before torquing it down