Gear case leak

[harvey lee]

2006 Chev Ext cab 4x4--155,000 miloes. Small V8

I noticed a spot on my driveway and after checking things out, I have a pin hole size leak in the middle of the gear case on one side. It is so small that when I wipe it off, it takes maybe 3 minutes to show a speck of gear oil leaking.

Here is what I thought I would do to try and fix it without buying a new one.

I drained the gear oil and then I am going to wash the side of the gear case down very well numerous times with brake clean, may use the whole can to make sure I have all the gear oil residue off that spot and much more. Then I will use the air blower and dry it well.

Should I use some emery paper and gently rough up the surface and then clean it numerous times again with brake clean or is the aluminum porous enogh that I do not need the emery paper?

Then I plan on putting some JB Weld on the spot and letting it sit for a day to make sure it is cured.

Then I will refill it and see if it has stopped leaking. Then of course I will watch it

Is the cause of the the fact the chain in the gear case gets a bit of slop and hits the case? If so, I built that area up a bit around the pin hole leak so it has a bit of extra thickness, not sure if that was needed but I added a little extra anyways.

Any of the auto experts believe this will work or am I wasting my time?

[CAMAN]

I'm not a huge fan of JB weld on pin holes and hairline cracks as it doesn't penetrate and actually fill the hole, just covers it up.

If this is just a small hole, or beginning of a hairline crack and still small enough, I would probably drill out the hole with an 11/32" drill, then tap the hole with 1/8" tapered pipe tap. Wrap a 1/8" pipe plug with some teflon tape and screw in. Should last the life of the case.

If you want a quick fix, clean the area thoroughly and drip a few drops of GREEN loc-tite 290 onto the hole. It should penetrate the hole and seal itself after sufficient curing. But may not prevent the problem from happening again if the crack/hole grows.

[harvey lee]

My son is a tool maker and suggested to drill, tap and bolt it bit in the spot it is, that would be very diffucult and the case would have to come out.

I talked to another mechanic and he said what I am doing will work but some day, it will leak again, will that be 1 year or 3 is yet to be determined.

[Jeremy airjer W]

Band-aids cover wounds, they don't fix them.

[harvey lee]

Only reason I put a band aid on this one is the truck will be done in a few years. Worst case scenario is that it only holds for 6 months and then I have to either put a new gear case in it or get ride of the truck.

I know in a perfect world I would just spend a grand or better and replace it but I may not have too. Only time will tell.

[BartmanMN]

Do a Google search on 'Transfer Case Pump Rub' and you can read many stories on solutions.

[Scott K]

Tom, what I would do is, either price a used unit, and replace it, or tear it down, drill a hole where it is leaking and weld it. Remember, there is a reason it is leaking, and you will find that out when you tear into it.

If you are just looking for a band aid, JB Weld will slow, or fix the leak for a while. I have done it several times in the past. They also make that 2 part puddy epoxy, that is like puddy, and you could drill a small hole in the case, and fill it with that stuff, it may seal better then JB Weld.

[harvey lee]

I watched a video on the issue with this transfer case. I could take it out, buy the new replacement part as that part would not rub the hole in the case.

I am going to expoy it for now and check on the price for the new replacement part, only problem is, I still have the small epoxied hole in the case I now have. Getting a used one will only give me the same issue as Chevy has issues with this pump in the case as it hits the case in time and wears a hole through it.

I would hope the new cases have that part issue resolved or I will still have another issue in time.

I read a thread on a fellow who did what I did and one truck he has driven for 20,000 and it is still holding just fine with no leaks, Who knows how long it would go.

It looks to me that the part that hits the case can only rub through so far and if I build the epoxy up heavy enough it may not wear through again. Who knows.

Poor Chevy design on the case if you ask me. One should not have to buy a aftermarket part to fix the issue. That part would only be good to put in if the case does not have any wear at the time of replacement.

[harvey lee]

Here is a service bulletion from GM on the issue and how they hide it until you are out of warranty. What a bunch of garbage. I guess this is how GM covers up thier bad products.

This bulletin is being issued regarding problems

encountered with holes in the New Process Transfer cases used in

all light duty pick up trucks.

Several customers have been reporting holes developing in their transfer cases, particularly in high mileage vehicles.

The source of this hole is from the internal transfer case pump rubbing against the housing and wearing through the case wall.

ACTION:

If the vehicle is within the specified warranty period service technicians should thoroughly clean the exterior

surface of the transfer case around the hole. Apply a suitable amount of GM Adhesive, Part Number 142239JB (JB Weld) to ensure

the transfer case leak will stop until the truck is out of warranty. Refill with the appropriate oil.

If the vehicle is no longer within the warranty service period, deny any problem exists and blame the hole on:

1) Improper maintenance

2) Collision Damage

3) Off road incident

4) Road debris

Under no circumstance should you acknowledge the condition referred to as “Pump Rub”.

If questioned, deny that it exists, except possibly in vehicles meant for overseas sales.

GM Bulletin #03-06-04-054

For Internal Use Only

[harvey lee]

If any of you have the years for this issue, I would go to GM and have them fix the issue correctly.

What a scam on GM's part knowing they have a issue and covering it up until ones warranty is out. Then they suggest to repair ir correctly.

[Scott K]

Tom, that is a made up bulletin, it was not published by GM.

[Scott K]

If you decide to replace the case half, here is the kit you will need to fix it. It really isnt to hard to do.

KIT

[harvey lee]

So, my epoxied hole will be fine with the new part? Or do I need a new half for the transfer case?

Thats good the bulletion was fake as it was real, that would be sad. I could see some companies today trying a cover up like that though.

Shoot me an e-mail if you would be interested in putting the new part in please.

[Scott K]

Tom, my experience with them is, you bought yourself a couple years. But, it is just a band aid. If you put the new pump piston in it, with a sleeve, and epoxied it good, you should be good to go.

[harvey lee]

I called and talked with a friend who works for GM and also builds trannies for race cars and transfer case for other shops.

He asked how I did the epoxy and I told him and also said I put 3 layers of epoxy over the entire spot for thickness.

He laughed at me and said I overdid it. He said the shop he works at does this if the customer does not want to spend alot more money to replace the needed parts.

As you stated Scott with it could go 2 years, he believed how I did it would would outlive the truck with the miles on it now. He said to watch it close for the 1st month and if it does not leak or drip that I should be good to go.

I guess I will now see how long I can make it last or how well of an epoxy job I did. Either I will get lucky or I will have another leak. Then I will have to see if the truck would still be worth the added expense. May be time by then to get a new truck too. Seems I always go for the 250,000 miles and the last 3 vechiles I have made it.

Chevy really missed the boat on this case. Buddy at Gm says they see this all the time and that there should have been a recall on these cases.

[BartmanMN]

Harvey I'd like to see a pic of your work if possible. Mine has a very slow leak, but I feel like it is only time until I need to make the same decision as you.

[harvey lee]

Here is what I did.

I cleaned the whole area with brake clean, use half a can.

Then I took some emery paper and roughed up the surface a few different times using brake clean between each emery papaer scuffing to get any dirt out of the grooves the emery paper could have left in those grooves so the JB Weld would hold well.

Before I applied the JB Weld, I also use my air gun and dried the surface to be epoxied very well.

Then after that dried for 24 hours, I emery papered the JB Weld area again and sprayed that down with brake clean so it was good and clean and applied another coat.

The JB Weld package states to have the air temp above 40 degrees ideally and my garage stays pretty warm or at least warmer than outside. I also use a 100 watt light bulb abd hung it on the cross support by the transfer case on a Chevy to make sure it was warm enough for the epoxy to cure well.

The GM friend of mine said one could use a coarser sandpaper as the back half of the case is made of magnesium as the front half is Aluminum and the Aluminum is much more poris.

I used the Original JB Weld as it has a higher pressure rating and withstands a bit higher temp. He said I could have use the Kwick set JB Weld but I may have overdone it a bit.

Frien told me the key to the success of this repair is to make sure you have the case where the epoxy will be applied as clean as possible. I used almost 1.5 cans of brake clean to make sure the case was as clean as possible before any epoxy was applied.

I drove the truck today about 80 miles and so far, so good. I will watch it daily as directed for approx 1 month and then every week or so.

I believe I have it cured but only time will tell.

if you have a Chev truck or whatever brand you have, make sure you get the correct transfer case fluid back in the case. many types out there.

If you have any other questions, shoot me an e-mail and I will reply with my phone number and I can further eplained over the phone the whole precess.

I know for the Chevy, the make a new part and sleeve to replace the one that came in the Chev trucks that cause this issue. You would have to drain the case and then take it out to replace the pump part.

friend also explained to me that when you drian your case, If it is overfull, it could have a bad inner seal and the ATF from the transmission could leak into the case so before you drain your case, what I did was pull the fill plug to make sure it was not overfull. Some will come out if it is full but it should not be that much. If you think you have to much in the case, then I would measure it to make sure it was not overfull.

Or, if your tranny has been low from time to time, that could be where your ATF for the tranny is going. Just mentioned it so you can check if your tranny has been low from time to time and you never see a drip on the floor anywhere.

Overall, a pretty easy fix and the main time for the job is the drying time for the epoxy. Friend said I went overboard on the layers of epoxy but I wanted to make sure I had that area covered well enough.

if you want to talk on the phone, shoot me an e-mail to this address

[email protected].

Just so you realize that the best way to fix the case and pump part issue would be to replace the part and he said if one epoxies the hole up well enough, then you would not have to purchase a new back half of the case.

I di tthis type repair as my truck has alot of miles on it and I didn't feel that I wanted to spend what is was going to cost to put a new one in. The part and fixing the case is less spendy if you can do it yourself.

If you have been leaking for awhile, I would watch the fluid level in the case or if it gets to low, you could or probably will burn the case up and then you will need much more. I was lucky enough to catch mine right away as I always look on the floor in the garage for any leaks of any type.

[BartmanMN]

Thanks. I have a very small drip. I could not really tell where it was coming from so I had brake cleaned it, but haven't been back under there since to look again. I did run through my local garage after my neighbor scared me with his story, but it appears I am still full so no concern yet. 144K on mine, so I am watching it.

[harvey lee]

I would get it fixed before it possibly could crack farther and then you could loose the fluid fast and then the case is gone if it runs out. Goona have to be fixed sooner or later anyways.

The repair job I did is really not hard at all. Just have to be without the truck for a few days so the JB Weld can cure. There is probably another brand epoxy to use but I have had very good luck with JB Weld in the past.

As I stated above, we used it on a transmission for the race car and that held very well.

If you were close to me, I would come over and show you how I did it as it is as I said, a darn easy job.

[BartmanMN]

I need to determine if I have a pin hole yet or if it is coming from a seal.

[harvey lee]

So far after 3-4 days, no leaks. Hope it holds like it is, otherwise I will be coming to see you Scott.

[harvey lee]

Update, after 1.5 months, no leaks and JB Weld job is doing great. We will see how long this cheap fix will go, I have a feeling for as long as I own the truck.