mensch53

Two days ago, my trans quit shifting into 1st or 2nd. So, knowing what I had learned from this forum about linkage, I jacked the car up on on the drivers side, crawled under, and realized that the bolt holding the 1st/2nd shifter arm in the trans was loose. Tightened it down and everything seemed fine. Then I noticed a problem...

Yesterday, I started noticing some problems with the drivetrain. When starting to turn from a dead stop, I feel clanking, virbrations, and it feels like the tires slip and grab strangely. Feels like something is wrong with the differential.

It looks like the body is sitting about an inch higher over the rear wheel on the passenger side than the drivers, which I have noticed before, but now I am wondering if something is wrong with the rear end/suspension.

So, did I mess something up when I jacked up the drivers side of the car about 4-5 inches?

Given the symptoms described, anyone have a guess what the problem is? This concerns me enough that I am going to take the car in to the vette shop this week, but I would like to have some idea of what to expect. I am guessing they are going to tear into the differential and tell me the gears are messed up.

Any input would be appreciated!

bob

The first thing I would do is suck out the diff fluid , put in new with GM posi additive. Then do a bunch of figure 8's in a parking lot and there is a good chance all will be fixed as far as the diff goes.

SHAKERATTLEROLL

From what you have said it sounds like an easy fix but as they say I could be wrong lol. But I would change out the diff lube and make sure to add the posi lube addiitive as well. Or you might just get by with adding the posi lube by itself.

Before I would take it to any shop I would try these two simple things first. Depending on the shop they may just do what I said or as you said they may tell you they need to rebuild the diff. It all depends on how honest the shop is and how bad they need funds.

SHAKERATTLEROLL

Now tell me how great is this forum . With in about 16 minutes you have two replies.

Hope it all works out.

mensch53

Haha. Amen. The only reason I knew how to deal with the shifting issue was due to the help I got here. I spend way too much time reading here!

mensch53

So, last weekend, I syphoned out as much fluid as I could, put in some posi additive and about half a bottle of 80 weight fluid. I went to a nearby parkinglot and drove around in circles and figure eights (much to the amusement of those watching.) The problem seemed to go away.

However, after driving to and from work (about 10 miles), the problem returned. Seems to happen only when the diff is warm after travelling long distances.

After making a particularly long trip today (about 30 miles), I pulled off the highway and it was really bad. I would come to a stop and virtually any manuver after would cause the rearend to pop and grind. I drove straight to the vette shop here in Tampa.

Apparently, my first mistake was not using GM posi additive. He is going to do a full service - pull the cover, drain everything, poke around, new gasket, refill with proper gm additive, some posi quieting additive, and new fluid. He said that will hopefully take care of it.

If not...who knows?

Any thoughts, words of advice, etc?

sweethence

My advice, Dont just assume you screwed somthing up, the car is 37 years old, it will creak and moan, just its way of telling you it needs attention

and also rememer the rule of coincidental gotchas. Basically stated that where if you change/ upgrade one thing on an old car the other old things get jelous so they start acting up to

Also I beleive, and correct me if im worng that the colloective wisdom here told you to change that fluid when you bought the old boy..... didnt follw our advice did you for shame mesch for shame... for pennace you must write on the board 25 times

i will listen to my buddies on the forum
i will listen to my buddies on the forum
i will listen to my buddies on the forum
i will listen to my buddies on the forum
i will listen to my buddies on the forum

GTR1999

I can't tell what year you have. If it's 68-69 then it has the old solid steel clutches in it, if it's 70-73 then it has the snowflakes and they are junk. If hte Gm additive didn't work then you'll have to check the posi for damage but most likely too much spring tension,worn clutches, and lack of lube in between them. If you built it the same as stock you'll be back there again, if you use fiber clutches then you'llbe back even sooner. Use new solid steels and tune it without the spring and it will resolve the clutch hammer and the clutch life will be extended too.

mensch53

Sigh. I know I know. Too much attention paid to getting the thing running and not enough to keeping everything else happy. So, here I sit stranded at work, nervously awaiting the call from the shop. (please let only be the fluid, please let it only be the fluid, please let it only be the fluid...)

gtr1999 - It is a 69, but I have no idea what is in there. All I know is that the rearend was rebuilt in 2003 sometime before I bought the car and there is no telling what was put in there at that point. I will keep your input in mind and will report back what the shop tells me.

sweethence

Ill send up a prayer to the C3 gods your shark will be ok

mensch53

They are a fickle bunch.

While you are at it, could you pray for a 350, a paint job, and for my convertible pin latch to stay closed?

sweethence

Indeed they are

and they frequently demand sacrifices of blood sweat and tears if you already havent found out.

you looking for a 350 complete or just a block?

mensch53

I am looking for the 305 Bubba put in to grow 45 cubic inches. If I had the time, money, and facilities, I would love to build my own. If I had more money, I would love to have one built for me and put in. Alas, I have none of the above, so I am stuck praying to the shark gods hoping that the 350 will just magically appear under the hood.

sweethence

as long as you are wishing right

mensch53

just got it back. they didnt see anything obvious when they had the rear end open. in the 2 blocks from here to the shop, everything seems fine, but i will know more when i drive home tonight.

Eddie 70

When I had my 79 the rear end did the chattering thing like you describe. What I did was take a hand operated pump and pump all that I could get out. I refilled with some no brand gear oil till the oil was just coming out of the diff. I went and drove the vette around the block a few times and also did the parking lot thing. I drove the car back home and pumped the no brand gear oil out. I put in the GM additive and then added Mobil 1 gear oil to the diff. That was the last time I ever heard from that diff.

When I added gear oil to the diff it was way more than half a quart of gear oil though.