Shrike

Since the 700 is a little longer than the 350, the yoke sticks back in the driveshaft tunnel a little ways and, under hard acceleration, hits the side. It doesn't hit hard, but it is very annoying. I tried to tap a small dent in the floor pan, but I can't get a very good swing with the hammer. I think I will have to jack the car way up, disconnect the driveshaft, and then smack it.
Anyone else have this problem? If so, how did you fix it?

Casper

Are you sure it's not the vent tube from the cat? Mine was and all I had to do was bend it a little to better clear the side.

gkull

The rear of the tranny should be bolted firmly to the crossmember with maybe a hard rubber shock mount. The rear diff. has a upper front forward rubber snubber that I put a solid aluminum spacer in years ago to make it have no movement.

That might be the real cause of the noise.

mrvette

I don't know if the 76 has a metal or fiber floorpan....if metal, and it's the source of noise,...well sometimes a BFH does cure the problem....now...if it's fiber...well prepare to wear that hammer on your head....

at any rate I had to cut my floorboard on the pass side to allow enough horizontal clearance....by about an inch maybe more....
to do that, I sliced down about a foot and back about a foot and then sliced out a section, prying the tunnel section over about 2 inches or so, held it with the tranny, and that allowed the cut out to close again...taped the underside and glassed it over....worked fine...

GENE

Bans25

I just noticed that my 700r4 (I haven't driven the car yet) yoke is very close to the pass side.. Also the dipstick tube is right against the pos batt cable :eek:

I am using the crossmember from BTO, but the tranny seems offset to the
pass side for some reason, I will have to do some measurments this weekend.

For those with 700R4's how close is the dipstick to the floor?

-Bill

P.s. I am about to measure the driveshaft distance to have it cut. Where do i measure from? I.e. How much of the yoke needs to be in the trans?

Robert8096

Is anyone using the crossmember from these guys??
http://www.bowtieoverdrives.com/68-81Corvette700R4.htm

Golden80

99.9% of the people that have a 700R4 in their C3 has this crossmember installed along with the tranny. They're great and know what they're doing.

Matt

Rolling Thunder

I've got it in mine, bought it when I bought the 700 from BTO.

Dave

xfactor974

I modified my cross member. I found that when the tranny was up there, there was a clearence problem. So I decieded to move the holes a little towards the drivers side to compensate. I'm hoping this will fix this delema.

Ozglide79

When I installed my 700r4 they didn't have a complete install kit with the modified trans. mount and cross member. What a PITA it was to fab the trans mount so it would fit. I think I had alot to do with convincing the owner that he should supply the complete kit (hours on the phone when he was at work and at home---he gave me his home and cell #'s---bugged the hell out of him till I got it right) because at the time he would just say "I build chevy transmissions, I'm not in the kit business". I also suggested that he get with the corvette mags and have an article done on how easy it was to install and what the results would be. The reason I say easy is because if I can do most anybody can (just remember to seat the torque converter properly--this almost cost me the unit before I got to use it). The only advantage I had is that I work for a reserve fighter squadron and I have access to the base hobby shop with lifts and tranny lifts. It also didn't hurt to be friends with the squadron fab shop super who has his own shop on the side (no govt. stock in my car or govt. paid time). He made my modified trans mount that bolted to the original cross member. I think the guy is rolling in cash now that he makes it so easy. If I would have had the crossmember and trans. mount he now sells it would have cut my install time to a quarter of what it took back then when I had to figure out the dimensions myself and wait for someone make parts for me. By the way, I don't have any clearance problems, I made my mount so I could adjust the trans. side to side and up and down with shims to get it centered properly:flag

gkull

I would fix it just like how I said. If the poopie doesn't move it can't bang anything. You shouldn't have any movement.

To the others that may have just noticed the motor is set over to the passenger side to give the drive train a straight shot at the pinion gear

Which is not centered on the differential. So if your jacking the tail shaft around your inducing side loading on the U-joints. They were built straight for a reason.

Gary79

when i did my conversion, i bought the trans adapter plate from bowtieod,$90,that bolted to my x-member,no problems. at the time they did not offer a new x-member. i have no problems with clearance. the amount to cut a driveshaft is the measured difference in length between your old trans and the 700r4. in my case my th350 and 700r4 had a difference of 3 inches,so the machine shop cut 3 inches off the driveshaft.

Eric 96

When I first bought my car, the 700R conversion had just been done. The dip stick, and the cooling lines rubbed against the tunnel. My tunnel is fiberglass, as are my floor pans. I lived with the annoying sounds for a while, then while under the car one time, I was able to adjust the cooling lines, and the noise is gone. But I do admit, there is VERY LITTLE clearance under there with that 700 tranny!!!!

vettedan

"under hard acceleration, hits the side of the tranny" If the tranny is aliened properly, you shouldn't have this problem. I've have drag raced and auto x, never witnessed this with my 4L60E. The hardest part was wrapping the dual exhaust around the tranny and through the crossmembers.

Mrvette-'76 vettes all have steel floor pan.

Golden80- I must be the 1% that used the stock crossmember with the 4L60e tranny. It works great and looks to be stronger built than an '82 crossmember.
Dan




[Modified by vettedan, 7:50 AM 1/16/2002]

chevluvr

I used the Bowtie on my installation and had to modify my holes like xfactor above but to the passenger side just a little. Seems to work fine and does not rotate and bump the undercarriage. Other than that I have enjoyed my conversion. Best of Luck!!!!!!! :yesnod:

mrvette

Vettedan, Yeh, I thought they did have steel floorpans, but not sure what years that was....at any rate I did my conversion some 4+ years ago from a '72 Muncie convertible, and kept the fixed crossmember, so obviously if my tranny goes, I either pull the engine, or cut the crossmember...tons of fun.....I did my own mounting bracket by cutting, bending and welding on the original mount...worked fine...


GENE

Shrike

I got my 700 from bowtie, with the crossmember adapter. I know it is the driveshaft, because I can see where it hits. It doesn't hit very hard, there is just a thin scratch on the side of the tunnel where the corner of the yoke occasionally touches; I mean if I had an extra 1/32" of clearance it would not hit. It only hits under heavy acceleration (like WOT).
gkull- I'll take a look at that, I know what you're talking about because I just replaced that rubber piece last year (unfortunately with another rubber piece).
Thanks for all the replies, I just wondered if this was a widespread thing.

gkull

Shrike. I did a home made cross member. On top of mine I use large washers as spacers. because I had the front of my motor tilted up to far when I welded it. Maybe you have some type of spacer that you could pull out for extra clearance.

I would never use the stock dual exhaust holes in the cross member for several reasons. Heat is one. Auto trannys don't like heat so keep the pipes far away. The other is - It's a pipe benders nightmare to try. The correct conversion crossmember is shorter to allow the exhaust pipes to go under and straight back 6-8 inches outboard of the stock locations.

vettedan

Mrvette-Like you, I prefer to do my own fabrications. I wish I could have found a vette like yours to install my conversion into. '68 thru '72 are my favorite years. Maybe my next conversion.
Dan