1985 front ring gear missing 3TEETH!

[Flyinmechanic]

Well, my tercels "click-click" when driving got worse and turned into a really bad thump and shudder. After replacing CV axle assy's., new loaded calipers, new rotors brake lines, (needed em anyway) I back up and, Yup, same nasty loud "crunch".

Removed front differential cover and found 3 teeth missing on ring gear!, pinion is somehow still intact? No wonder it drove better in 4wd!! IT STILL CAN OPERATE IN 2WD! amazing car.... So I ask,

1) Is this a "weak-link" on these vehicles?

2) New ring & Pinions available?

This is my Idaho backcountry backup vehicle, so it is worth fixing up, I have the factory shop manual, what are some recommendations as to fixing and some possible mods for backcountry mountain switchback driving? I am 60miles NE of McCall, ID on Southfork of Salmon. Thinking of buying a parts car and O/H the transaxle then swapping, open to suggestions!
Thanks,
Doug

[Petros]

Welcome to the list!

Sorry to hear of your problems, diff are usually pretty durable and hold up if not run dry. Sometimes with lots of miles they get bundled up like yours, luck of the draw I guess.

There is a local yard with a front diff available here. I could pull it and ship it to you. Hopefully the metal parts did not get into the main trans gear cluster and do any damage. Make sure you flush out the whole trans if you are going to reuse it, just incase. (the diff and main gear cluster is in separage compartments but they share the same gear oil, changes are good it is okay, but it could have picked up shavings into the main gear box). Protect that trans, they have not been any made since 1987 and they are all the same age, still good ones to be found but all have lots of miles on them.

If you swap out the whole trans with a good one that will solve the metal contamination issue, but you need the right ratio diff. If you get a parts car or a whole transaxle you need '85 or newer, you have the much desired 4.1:1 diff ratio, '83-84 have 3.73:1 (do not mix them up!). In fact one of the few times I have see trashed diffs was when some put the wrong ratio trans in the car and did not match the rear diff (if that is a possibility on yours you need to check it out). The trans will swap and there is no external indication of diff ratio on either front or rear diff (you either have to count teeth or look for the ratio stamp on the edge of the actual ring gear).

good luck.

[Flyinmechanic]

Appreciate the info and offer! I guess a parts car would be a good idea for these. let me check out the local yards here first. Yes the ratio is 4:1 both ends. So I guess hard parts like ring & pinion are not available?
All fluids were at proper level, did not run dry, in fact, this car was driven over 70 miles this way!! ouch....but it drove as if the rt. side cv axle was trashed.

Probably pull the whole diff/trans assy. and check everything over, then decide course of action.
Thanks Again;
Doug

[Petros]

where are you?

If you want the front diff off the local PicknPull do not wait too long, I asked and they said that car (that whole row of cars) will go to the crusher in nine days.

[Flyinmechanic]

I am 60mi. NE of McCall, ID. If you can get to it, go ahead and pull it. That would be great. I commute into the Boise Airport also.
let me know, how much $$ they want for it and add something for your time!
Thanks again;
Doug