Things to check while transmission is removed?

[findtherightlin]

Hey everybody, long time lurker first time poster here. This site has helped me a bunch already, so thank you to all those that have contributed. Wouldn't have been able to get my shift lever off or find a tow hitch without you guys. Ok, so on toy question.

I have pulled my trans from the cruiser as it was leaking pretty heavily from the input shaft area. Pulled the cover and the input seal disintegrated when I touched it. The liquid gasket was also pretty roasted. I have a new input seal on the way, along with a clutch kit from cruiser corps. Pretty sure the clutch I have got contaminated because it was slipping at one time, although it was fine when I pulled the trans. I also ordered a 1 piece oil pan gasket for the motor as I have a slight leak from the front of the pan. I have seen people suggest doing the rear main any time you have the trans out, but I'm not sure I need to as the PO had the motor rebuilt a few months before I bought the truck. Motor runs great, my old machanic Jim Dickey (RIP) said it was very strong when I had the truck in his shop. My question is should I be looking at anything else while I have trans pulled? It was a bit of a chore getting it out, so I'd like to check everything I can before I reinstall. Should I just do the rear main as well? Any insight or suggestions would be awesome.

 

[4Cruisers]

A few odds and ends that aren't readily apparent:

Check reverse light switch function (transmission) and 4WD indicator light switch function (transfer case)

Upgrade detent spring on front drive shift shaft (see my Post #8 here: Transfer case front output shaft shift linkage) - the stiffer spring helps keep the front drive engaged

Extend breather on transfer case (search MUD for some ideas, including my recent Post #21,310 here: What have you done to your Land Cruiser this week?)

Find and write down production date code on transfer case (good info to document)

 

[OSS]

Yes-
Do this.
One of the possible causes of transfer to transmission oil migration is the one way breather installed in the transfer case. It lets air out (as it heats up) but doesn't allow air in when it cools down. This cooling after every engine shutdown creates a vacuum inside the transfer case and when the seals age, oil can get sucked from the transmission into the transfer case, especially on the 5 speed transmission.

If a breather hose extension is installed in the transfer case and routed up to the engine compartment, the transfer will then breathe freely and air pressure will equalize.

ARB makes a differential breather kit that has the hose & fitting & filter mount. The brass part that goes into the transfer case you can get at McMaster Carr

 

[findtherightlin]

Yes-
Do this.
One of the possible causes of transfer to transmission oil migration is the one way breather installed in the transfer case. It lets air out (as it heats up) but doesn't allow air in when it cools down. This cooling after every engine shutdown creates a vacuum inside the transfer case and when the seals age, oil can get sucked from the transmission into the transfer case, especially on the 5 speed transmission.

If a breather hose extension is installed in the transfer case and routed up to the engine compartment, the transfer will then breathe freely and air pressure will equalize.

ARB makes a differential breather kit that has the hose & fitting & filter mount. The brass part that goes into the transfer case you can get at McMaster Carr
View attachment 2028732

Thanks for this idea, but I actually had Jim do some custom work on my 4 speed trans/t case. He uses hollow, tapped bolts for the fill bolts on both the transmission and t case. A hose connects the 2, so if oil is pulled from one to the other it just flows back in thru the hose. Really nice design that Jim highly recommended.

 

[NeverGiveUpYota]

Thanks for this idea, but I actually had Jim do some custom work on my 4 speed trans/t case. He uses hollow, tapped bolts for the fill bolts on both the transmission and t case. A hose connects the 2, so if oil is pulled from one to the other it just flows back in thru the hose. Really nice design that Jim highly recommended.

That is a bypass hose which IS nice option when funds and time don’t allow for pulling and replacing the seals but it’s not recommended for long term use.

 

[findtherightlin]

A few odds and ends that aren't readily apparent:

Check reverse light switch function (transmission) and 4WD indicator light switch function (transfer case)

Upgrade detent spring on front drive shift shaft (see my Post #8 here: Transfer case front output shaft shift linkage) - the stiffer spring helps keep the front drive engaged

Extend breather on transfer case (search MUD for some ideas, including my recent Post #21,310 here: What have you done to your Land Cruiser this week?)

Find and write down production date code on transfer case (good info to document)

Thanks for the info! I'm guessing that detent spring is under the 19mm bolt I'm seeing on the t case? Seems easy enough to get to. I never had a problem with it coming out of 4wd but I'll upgrade it anyway. I think I'm good on the t case breather, as I mentioned in the previous post. Doesn't seem like it would do me any good as my trans and t case share oil thru the hose. I'll try to get a picture of my setup once the lighting is better outside. Can't really see it in the CA afternoon sun.

 

[findtherightlin]

That is a bypass hose which IS nice option when funds and time don’t allow for pulling and replacing the seals but it’s not recommended for long term use.

What seals are you talking about? And why isn't it good for long term use?

 

[NeverGiveUpYota]

The bypass hose is considered a bandaide. You’ve got the trans out so the seals that are allowing migration will be replaced most likely, then ditch the hose.

 

[findtherightlin]

The bypass hose is considered a bandaide. You’ve got the trans out so the seals that are allowing migration will be replaced most likely, then ditch the hose.

I'm not sure I have migration at this point, Jim just suggested doing the bypass hose while he was supposedly replacing my input shaft seal. Is there any way to tell if I have migration without splitting the trans and t case? How big of a job is replacing the seal between the 2? I've done all the work myself so far, and I'm trying to keep it that way. Haha.

Oh, and why would I ditch the hose after replacing the seals? Seems like it would be good to have just in case migration happens again. The hose isn't in the way or affecting anything....

 

[NeverGiveUpYota]

I'm not sure I have migration at this point, Jim just suggested doing the bypass hose while he was supposedly replacing my input shaft seal. Is there any way to tell if I have migration without splitting the trans and t case? How big of a job is replacing the seal between the 2? I've done all the work myself so far, and I'm trying to keep it that way. Haha.

Oh, and why would I ditch the hose after replacing the seals? Seems like it would be good to have just in case migration happens again. The hose isn't in the way or affecting anything....

Fluid can migrate one way or the other. The only way to know is to keep the hosevoff and make frequent checks to evaluate which one is getting the excess fluid.

 

[NeverGiveUpYota]

If I’m way off someone please speak up... @mwebfj60.

 

[findtherightlin]

Fluid can migrate one way or the other. The only way to know is to keep the hosevoff and make frequent checks to evaluate which one is getting the excess fluid.

Jim didn't seem to think the migration was a problem as the hose allows everything to equal out. I know it's not how Toyota designed it, but if they both use the same oil I'm not sure why this wouldn't work long term.... I'm only going off Jim's opinion, but he sure as hell knew more than me. My trans and t case both shift/drive smooth, and no leaks other than the input shaft seal. I'd like to avoid tearing them apart if I can.

 

[Spike Strip]

Jim Dicky passed away?

 

[findtherightlin]

Jim Dicky passed away?

Unfortunately yes. His son Randy said his cancer finally got him. To make things more tragic, Randy and his girlfriend passed away in a fire in the shop about 3 months later. I believe they were living in the shop at least part time because the fire happened at night.

 

[Spike Strip]

Wow. I saw where it looked like his inventory was being sold off, but I thought he was retiring... Sad news.

 

[MDH33]

while you have the h42 out, replace it with an H55.

 

[findtherightlin]

while you have the h42 out, replace it with an H55.

If you find $3k laying around, send it my way. Eventually I will do the 5 speed, which makes me even more reluctant to crack this one open to change seals.

 

[findtherightlin]

@NeverGiveUpYota if I do the extended t case breather as suggested it should alleviate migration regardless of if the seal is bad right? Doesn't it need the vacuum created while cooling down to pull fluid? If anyone else has any info or suggestions for me, please let me know. I saw a thread with some selling steel braided hose to replace the rubber I have. Jim told me I could use 80w-90 gear oil in both the t case and trans. Anyone else doing this?

 

[NeverGiveUpYota]

@NeverGiveUpYota if I do the extended t case breather as suggested it should alleviate migration regardless of if the seal is bad right? Doesn't it need the vacuum created while cooling down to pull fluid? If anyone else has any info or suggestions for me, please let me know. I saw a thread with some selling steel braided hose to replace the rubber I have. Jim told me I could use 80w-90 gear oil in both the t case and trans. Anyone else doing this?

Breather won’t lessen migration. If the seal is shot then it’ll migrate until it gets replaced.

 

[Chad717]

Yes-
Do this.
One of the possible causes of transfer to transmission oil migration is the one way breather installed in the transfer case. It lets air out (as it heats up) but doesn't allow air in when it cools down. This cooling after every engine shutdown creates a vacuum inside the transfer case and when the seals age, oil can get sucked from the transmission into the transfer case, especially on the 5 speed transmission.

If a breather hose extension is installed in the transfer case and routed up to the engine compartment, the transfer will then breathe freely and air pressure will equalize.

ARB makes a differential breather kit that has the hose & fitting & filter mount. The brass part that goes into the transfer case you can get at McMaster Carr
View attachment 2028732

Sorry for the thread hijack, but I'm looking for this part on Mcmaster Carr and I'm not sure i'm finding the right one, does anyone have a specific reference? Thanks!