Official Crawlbox BS thread!

Usually if you have the shifters pulled, this is a nice area to get a pry bar to help push off the dowel pins and break the rtv.

 

i had luck with heat in the past

 

Ooh good idea. Will def be trying this tonight

I the case shifters pulled, but pulling the trans shifter might give me the room up top.

Also going to give that a whirl.
Thanks for all the suggestions. Usually I've had good luck with pulling RTV parts apart, but I'm sure the cold weather isn't helping.

 

Finally got my cases out and broken apart. Nothing blatantly broken, so I dunno what was causing the original new recent noises I was hearing.

Not sure what to make of this what looks like heat affected zone on the end of the rear case coupler that rides in the bearing on the rear adapter. Looks like the coupler was spinning inside the inner race of the bearing.



Also some wear on the other male spline end of the coupler.



It's my first time pulling these back out after my initial install ~30k miles ago, so not what the norm is as far as wear goes. Any opinions/advice welcome. As of now, I'm planning to just throw it all back in.

 

Rear coupler is most definitely spinning in that bearing.
At a minimum I would get that bearing out of there and replace it.
If the truck can be down for a few days, I would look into if the TG adapter can handle/fit a dual row bearing.
https://www.marlincrawler.com/docs/mc07/index.htm Good read, don't focus on the 101% better but more on the research and measurements which are good.
How does that shift fork coupler that rides on the male coupler look? What's the teeth look like? Appears to be a lot of back and forth abnormal wear.

**Bearing is MRC 5209CG** dual row

 

I know initially, the tg adapters were having issue when use with MC dual row bearing. IDK if that’s still the case. Several people I know has that current setup (TG adapters with MC 4.7xD or 4.7 comp) and no issue.

 

Definitely interested in throwing in a double row bearing if it'll work. Sound like it's possible according to @02hilux.
@02hilux can you elaborate on what the issue was with running the double row bearing in the TG adapter? This is the first I've heard mention of that even being a thing. I know a few people with my same TG adapter and marlin gear setup, but all just use the factory installed single row rear bearing.

For the shift collar, nothing is standing out to me on initial inspection. The wear only seems to be on the coupler as far as I can tell.

 

Biggest thing on the the double row is to not use the fill slot type as that was known to have issues. MC was big on it not being issue, but had a few customers proved otherwise on forum posts. Tried clocking the fill slot at 12* position but still had issues. So the

$231 MRC 5209CG Angular Contact Ball Bearing, Double Row, Snap Ring, 30 Degree Angle Contact, 45 mm Bore, 85 mm OD, Silver

MRC 5209CG was tested and tried in Inchworm adapters to remedy this problem before that got out of the business. I know MC still sells adapters under Inchworms design, but not sure which bearing style they use now.

 

Wym fill slot type?

 

3209 One of the few reference threads, alot of this talk and pics uploaded when photobucket uploads were free. Now most are gone.

 

this is the bearing i put in mine after my marlin one pooped a bearing out

$231 MRC 5209CG Angular Contact Ball Bearing, Double Row, Snap Ring, 30 Degree Angle Contact, 45 mm Bore, 85 mm OD, Silver

https://www.amazon.com/dp/B00DBO77US?ref=ppx_yo2ov_dt_b_fed_asin_title

 

Ah got it.
So my measurements confirm it'll fit height wise. But the question is how the retention mechanism will work. The TG adapter uses two shims on either side of the bearing and then a blue stepped ring that gets clamped down via the allen head bolts.
In the marlin pics, looks like the external bearing snap ring sits on the face of the adapter and gets held down with those same style bolts. But since I don't have any dimension on where the snap ring groove is on the bearing, I'm not sure where it will sit and if it'll land perfectly on that shelf where the blue ring fits into.

Regardless seems like I'll have to machine down the height of the solid spacer that goes between the rear coupler and bearing to account for the added bearing height.






Note these measurements are with that bottom shim in the bearing pocket.


Guess I'll just order the $120 bearing and find out myself...

 

Yep, this is the one I have as well, has the higher 6000+ rpm for peace of mind as well.

 

@ToyRyd04 what's the function behind the thrust washer detent ball?

 

Keeps the actual thrust washer with the notch from spinning. Helps aid against deflection, similar to what the double row bearing does. OEM toyota uses the same design so it was copied over on the design on both MC and TG designs. If it got misplaced, I think Yotamasters and a few others might sell replacements. Forget the size....

Looks like MC has them, 6.35mm.

 

Interesting. My rear coupler doesn't have that.

 

That's interesting.... got a few pics?

 

Okay I was wrong. The coupler does have a spot for it, but the thrust washer doesn't have a receiving end so there aren't any provisions on this setup to accommodate that detent ball as far as I can tell.

The splines on the rear case input look sort of rusty almost too. Not sure if that's because they were starting to fret, or from maybe using coper anti seize when I initially put it together. Can't remember.

 

Interesting, that a thick spacer being used instead. Is this a complete TG crawlbox with 4.7s? Or a TG adapter with MC 4.7s? Original owner?
That's definitely fretting on the coupler/ rear case input.

 

bought TG adapter kit, got a housing off TW, gears from MC, and all the misc bearings and other missing parts from Yotamasters. Original owner built up by me.

There's no mention of a detent ball there in the instructions, but I find it weird that they have a spot for it.




Glad I caught the fretting now rather than getting stranded. I hope the splines aren't too far gone. Feeling them with a pick, I don't notice any pronounced steps in the length of the profile where the male and female splines engage with each other.
If I can get the dual row bearing to work, hopefully that helps prevent any future fretting. I assume there's just too much deflection going on there....