rear actuator drift pin issues

[IdahoDoug]

While yours may be recalcitrant, mine's downright reticent! Actually the pliers comment was just to indicate difficulty of movement is still beyond fingers. I'm moving it by spraying PB Blaster on the shaft, tapping it in with a plastic hammer and brass drift, then putting an allen key through the hole and pulling it back out with a small crowbar. The crow bar I ground so it has a slot wider than the shaft, so when I pry it pulls up against the allen key. At first it was quite reluctant. My Syncro sat for 7 years, and I suspect the owners didn't use the rear locker much if at all even before that. So it has quite a bit of grundgey old crud. In fact, the gear box oil drained looking normal, but then the second drain at 200 miles looked terrible. I think the fresh fill with its fresh additives began dissolving a layer of sludge - thickened gear oil from years of sitting. So who knows what the other end of my actuator shaft has on it?

Does anyone know if the actuator shaft is immersed in oil when it is just sitting? I suppose I could go crawl under and guess the oil line....

[Aidan]

no it is only minimally splash lubricated with whatever lube is being run in the box, most of the problem is differential corrosion between the hardened steel shaft and the alloy sleeve just infront of the oil seal, ie from the outside water wicks in and then you have some weird oxide build up binding the two together, if stood for that ammount of time I'd say drop the box, pull the bellhousing and strip out the difflock pin and sleeve, split them clean them and then ream them together with lots of oil untill free and easy and then reassemble, means you get to inspect the crown and pinion head too - it's only 4 hours work first time to pull the gearbox out on your own on axle stands and then you can do the tank straps and the fixed brake pipes as/if required - Jed can now do a gearbox out and in in 2 hours on his drive at home

[IdahoDoug]

Heh - you make that sound almost pleasant work!! Hmm. So it's that whitish powdery oxidation you find between alloy and dissimilar metals, eh? Crap. I don't think that dissolves well.

I won't be pulling the gearbox until this coming winter. I have been working on this vehicle for two years. It started as a non runner. Now it's in essentially expedition shape. The final change will be a gearbox rebuild and replacement of the notorious 3/4 gear synchro that is known for cracking. But I'm a week from the first trip ever, so once I install the new CVs arriving Monday, and tend to a half dozen minor things like reinstalling the cleaned headlights, mounting aux lights, etc she's ready. The locker can wait as I will merely reinstall the new vacuum activator onto the shaft once it frees up. In the meantime, I guess I have a fully manual rear locker. As in "slide under the rear, tap the shaft in, drive off, repeat to pull out shaft" Heh. Positively Neanderthal...

DougM

[bhpdub]

Heh - you make that sound almost pleasant work!! Hmm. So it's that whitish powdery oxidation you find between alloy and dissimilar metals, eh? Crap. I don't think that dissolves well.

I won't be pulling the gearbox until this coming winter. I have been working on this vehicle for two years. It started as a non runner. Now it's in essentially expedition shape. The final change will be a gearbox rebuild and replacement of the notorious 3/4 gear synchro that is known for cracking. But I'm a week from the first trip ever, so once I install the new CVs arriving Monday, and tend to a half dozen minor things like reinstalling the cleaned headlights, mounting aux lights, etc she's ready. The locker can wait as I will merely reinstall the new vacuum activator onto the shaft once it frees up. In the meantime, I guess I have a fully manual rear locker. As in "slide under the rear, tap the shaft in, drive off, repeat to pull out shaft" Heh. Positively Neanderthal...

DougM

That sounds like an easy solution....As long as once you have tapped the locking pin in, you can then actually pull it out again!

[IdahoDoug]

OK, need some help. OK, got the switch out, dribbled in oil. Now I've got new info and unexpected response.

Before I pulled the bracket, the bracket and snap ring held the alloy bushing in place when I pulled the shaft in and out. Now when i pull the shaft out, the alloy bushing comes with it (which tells me the friction is in that alloy bushing). I can pull it out until the O ring is visible, and then the large diameter cylinder behind that as well. I don't want to keep pulling and hear something in the diff fall off. So can someone tell me what will stop that inner cylinder? I want something to hold it in, so I can pull on the aluminum bushing, pull the bushing off the tip of the acuator shaft, then be able to clean the inner surface of the aluminum bushing and slip it back in place. Then bolt it up and be done. I think the other end of the shaft inside the diff is secured with a roll pin to something - that shift fork like part? But I want to be sure that its OK to pull the entire aluminum bushing out, with that large diameter cylinder behind it. I assume the large cylinder (same dia as bushing and hole in gear case) is merely a guide to help support the actuating shaft. But I'd hate to find out if I keep pulling that cylinder all the way out of the gear case, a shaft key or the return spring will fall off. HELP!!!

I cannot find a diagram of what that large diameter tubing is around the actuator shaft to tell me what will happen if I keep pulling it out of the case. Any thoughts?

DougM

[IdahoDoug]

Update. All is well. The locker actuator rod is so smooth it instantly flicks itself out with the internal spring, and I've partly reassembled, to finish Monday when the new vacuum actuator and CV joints arrive. I simply resecured the alloy bushing with the bracket, then worked the locker shaft in and out a bit with the switch hole full of PB Blaster. Couple hours later slid under to check the action and it is completely free and fast moving. Hope to have it back on 4 wheels by late Monday night. Thanks for the help.

DougM

[jes*b]

Yep pretty much exactly as mine went except when the guide / o ring showed itself I was straight on the phone to Aidan. Secured with bracket and new circlip then back into in and out etc. Well done.

[IdahoDoug]

Aaaaandddd a followup. Finished torque-ing the new CVs in place this evening, and took it for a drive. The locker works even faster than my other vehicles, which have electric lockers known for being quick to engage. Did it 10 times and each time very fast to engage and even faster (instant) to disengage. So from frozen locker shaft to flawless operation without pulling the box.

Regards,

DougM

[torchy]

should be a spring, but it's bellhousing off to get at the rollpin to remove the shaft to fit one if it's not there, as long as it is working freely it should be ok, the spring just means that the default position is OFF

Thankfully it has a spring so mine does release but the "ball" at the end of the actuator has broken off. So it's vacuum on and fingers crossed for off A mechanic tried to drill it out a while back but no luck, Any one know what material it is before I have another try? also there was a little worry at the time as to how deep to go, anyone know what depth the hole is from the end of the shaft.

Many Thanks.

[Aidan]

it's some sort of HT steel but not that hard, use lots of rost of or similar rust dissolver to wash out the rust and crud and nice sharp 4mm drill bit, will get it loose then use magnet to extract the remains, if you call me when I'm in the workshop I can measure the depth of the the hole but the shaft itself is well hard you'll know when you are through if the remains can't be extracted and you are drilling it out

[IdahoDoug]

While useful, the depth would not be critical, just need deep enough for a new shaft to go in, but if you drilled a MM or two deeper everything would still go together fine with just a slight fiddle to line up. The end is not really a ball. The shaft is simply narrowed where the roll pin holds it. I'd be tempted to forego drilling and use a threadlocker type product to hold the shortened actuator shaft in the hole. Something that would hold it well, but that could be broken loose later. The forces are very light in use. I'd rough up the remains of the shaft for a better grip.


DougM