Man-A-Fre Transmission/T-case oil bypass kit: The Job

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So last week when I checked my transmission fluid, I got the steady chug-a-lug of excess fluid coming out when I removed the plug. The T-case was also on the low side with no real signs of leakage. After searching the forum I came across the oil bypass fix for when the seal between the two goes out and the t-case starts pumping fluid into the transmission. This appears to be a semi-long term fix until you can drop it to replace the seal. I like coming up with fixes, but for this one the Man-a-fre kit seemed like the most cost effective way to go…figuring in my time and coming up with parts on my own.

This weekend I went ahead and did the job. Pretty easy to do, and I definitely noticed a difference when driving the rig afterwards. Very much smoother, and a clunking sound I was getting before was no longer there.

William
Oil bypass kit 1.webp
Oil bypass kit 2.webp
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Most likely those hose clamps have caused damage to the hose. That hose is designed to work with those hose fittings with no clamps. One mfg specifically states in their catalog "CAUTION: Sealing integrity may be damaged by the use of clamps"
Using clamps cuts the inner liner of the hose and starts a downward spiral. I have seen that hose and fitting assembly hold over 100 psi engine oil pressure without any clamps. The hose is rated to 300-350 psi (depending on model & maker) and the fitting itself to 5000 psi.

I would remove the clamps and very, very carefully cut the hose off the fittings (you will not be able to pull it off!). Do not knick the fittings in the cutting process. Shorten the hose the minimum necessary and re-install on the fittings.

If no clamps makes you nervous, then use either safety wire in two wraps or a Thomas & Betts (ONLY!) tie-wrap very carefully placed between the barbs of the fitting. Pull either down to only snug, definitely not tight.
 
NT's right,

Did MAF send those hose clamps with the kit?? Push lock hoses do not need the clamps..

Even more so in a seriously low pressure system as is shown..
 
yeah, don't need the clamps.. I run those lines with push-lok fittings on fuel and oil systems all the time and have never used them.
 
DOH!!!:bang:

No, there were no instructions at all with the kit. Luckily I didn’t clamp them too tightly. The hose felt like it was holding firmly so I put them on for insurance. Snug at best. Thanks for the heads up!


William

Don't feel bad....I think that is the story of my life. Every time I think I am doing something extra to make things better it has the exact opposite effect.
 
Sounds like MAF needs to at least include a note saying that the use of hose clamps voids their warranty or something. If you're not familiar with this type of fitting, and few people are though they're getting more common, then a hose clamp is sort of expected.
 
By pass install

Hose clamp no no, good information I would have put the clamps on too! That looks so easy even I could do it and think I will. Thanks for an excellent write up. :bounce::bounce::bounce:
 
Good write up..........But can you please not use YELLOW....kind of hard on the eye balls
 
I have siminlar but opposit problem that oil goes from tranny to t-case.
Does kit also applicable to my case?
 
OK stupid question, is this automatic only?

There are no stupid questions.

This kit is for manual trannys - because it uses the same gear oil as the transfer case. The auto uses ATF.
 
Glad I asked. I dont have the current seal issue but no reason why not to nip it in the bud now.

I tend to associate Transmission fluid with ATF and Gear oil with manual
 
So after I got my kit, with no teflon or instructions...I wrote MAF and asked about hose clamps and seals for the fill hole ends..no reply.

So I did not use any sealer on the threads..no leaks, been on for 6 months (which is less than 1K miles).

I had a @#%***!! of a time getting the hoses on the L fittings. using a vise and pliers I still did not get the hose all the way on the fitting. So, I used hose clamps. If the inner coating can be harmed by a hose clamp I sure as hell ruined it trying to get the hose on the fitting, (lubed it up still too tight). So in my case the hose clamp may be harmful but it is a moot point since I ruined the hose putting it on. In the long run I'll change the interior seal before the hose deteriorates. This is a good thread..should be included in the FAQ about the tranny/transfer fix..
 
A note on how to assemble those hose ends to the hose itself.

Clamp (carefully!!) the hose end in a vice with the part that the hose fits over horizontal. Lube the fitting and the ID of the hose. I use engine oil unless ATF is going to be inside, then I use ATF. Grab the hose by hand below where the hose end will sit when done. Wrap your second hand around the first. Get your body behind it, lock your hands into your gut, and push the hose on. This is a "Chinese Finger Trap" kind of deal, you want to force the hose to get shorter as in the process of doing that it will also get bigger and fit over the hose end barbs more easily. I won't say it's easy, just easier.

For some reason the -8 size is the hardest, harder than either the sizes bigger or smaller than it. This kit looks to be -6, so take comfort in knowing that it could be harder! If it's -8 then take comfort in knowing that you've seen the worst!

When the hose end is one of those with a bent tube I clamp an adapter fitting in the vice, and tighten the hose end onto it instead of clamping the hose end directly.
 
i just did it last month..super easy...use gear oil inside the hose and on the fitting and they slide on with firm pressure no vice or pliers, just your hands...

cost was $65

to like 20 min. to install
 

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