drive shaft coming through the floor at the rear of the tunnel

[Tom R.]

1965 c2 drive shaft coming through the floor at the rear of the tunnel. help!!!! what to do ?

[Patrick B.]

I would start by making sure the snubber bracket was bolted tightly to the rear end housing and replacing the snubber bushing between the bracket and the frame. Make sure there are the right number of washers and maybe add more if necessary.

[David H.]

1965 c2 drive shaft coming through the floor at the rear of the tunnel. help!!!! what to do ?

Tom

Years back, Bairs Corvette put out a "100 Points to Check" video. One part dealt with a C2 with sagging floor. That floor was being held up with wooden blocks sandwiched between floor and frame. Seemed like this was not an uncommon occurrence. So you are not alone.

What video didn't say, was how to repair.

Expect suggestions will vary body off or body on. Body on, I'd suggest getting floor back to original clearance then glassing in a support structure.

Expect you'll get responses from folks that actually know what they're doing.

Dave

https://www.bairscorvette.com/techinfo/techinfosearch.html?product_search=video&depth=0

[Leif A.]

I would start by making sure the snubber bracket was bolted tightly to the rear end housing and replacing the snubber bushing between the bracket and the frame. Make sure there are the right number of washers and maybe add more if necessary.

I agree with Patrick on this. Additionally, the fiberglass floors of these cars tend to "sag" over the years and can come in contact with the rear drive shaft u-joint, especially when the snubber bushings are shot. A "cure" for the floor sag is to put a couple of rubber hockey pucks on the transmission crossmember on either side of the transmission tail shaft area. This will raise the floor and help it clear the rear u-joint area. Do both of these things and your issue will be resolved. Also, make sure your luggage stop is completely attached and not loose.

[Mark M.]

It sounds like you may have whats been called broken spine syndrome. More common on 65-67 as 63,64 has extra body mount brackets. I've fixed a number of these. What usually happens is the fiberglass sags and breaks away from the bulkhead behind the seats which is sheet metal riveted with aluminum rivets to the body and the rivets also give out. Convertible bulkheads also have spot welds on the outer ends to the bird cage. If that's the cause the quick fix is as Leif has said to place spacers on the frame to hold up the sagging body. The better way to fix can be done with the body on. You would have to pull the seats and carpet out, possibly pull out the bulkhead, raise the sagging area of the body and do the fiberglass repairs and reinforcement as needed. Repair rivets to bulkhead that let loose. That part can be challenging with the body on as the crossmember is right below the rivet heads. I also use bonding material on the bulkhead to the fiberglass. The front rear end bracket on the frame and the bushings there can also cause the noisy problem. If I remember correctly it would make more noise on accelerating and less on coasting. Either problem sounds alarmingly loud in the car. Hope this helps. Paragon use to sell a short 10 page manual called 1963-67 bulkhead repair manual.

[Steven B.]

Tom, I agree with Patrick for the first step. Years ago I helped a friend Bill with this issue on his '66 convertible and we replaced the snubber as the original was deteriorated. A year later had rubbing again. Bill had a habit of carrying as many bags of salt in the winter back there and also Home Depot trips for Sakrete! The floor and bulkhead separated so we had to go the way Mark suggests. Good Luck Tom!

[Mike T.]

Tom - There's a chance it's 'all the above' but one relatively easy place to start would be that pinion snubber. On my 65 L78 Roadster, the snubber looked to be in good condition...when viewed from below. Since the upper bushing is hidden inside the snubber bracket, it's difficult to tell whether it is shot or not. Check out the pics starting with the pic from below leading most to think it's gotta be good and then, the parts laid out after removal. This by itself might not be the cure-all but couldn't hurt.
Mike T - Prescott AZIMG_4722.jpg

[Mark M.]

In my opinion the original upper snubber cushion for 63-79 was made too small. Most I've pulled out which have been in for a number of years are crushed down too much and or tearing. The best replacement is now hard to come by. I've used it for decades. The GM 14010397 upper snubber cushion for 80-82 which I believe is discontinued. I've seen them on e-bay both correct and a number of times, what looks like a 73 up body mount mis labeled by hand. The 14010397 is a larger diameter version of the 63-79 which is much better. Another route would be to use an after market urethane upper which usually is larger diameter than 63-79.

[Tom R.]

Thanks to all who have responded. Replaced snubber bushings 2 yrs ago, bottom bushing still looks good. I'm afraid I'
going to have to explore the raising of the floor remedy.
Once again, all responses are greatly appreciated.