Stewart

I got my 4.10's in about two weeks ago, and hadn't gotten a chance to take it out on the highways untill about last week. Stock the car would exhibit some vibration when above 100mph after letting off the throttle which wasn't too bad but still very noticeable. Witht eh 4.10 gears the vibration begins at about 85 and up, if I accelerate to say 90 and let off the gass the car starts a pretty annoying/worrisome vibrations. Once I hit 100 the vibration is so bad I'm scared to go any faster, the vibrations when decceleration are tolerable, but the severity of it at 100 mph just doesn't make me feel safe in the car. This happens even when I throw it in nuetral so I'm tempted to blame the driveshaft or something related. It definitely did this before my gear swap but it's just more noticable now since going 85 now was probably more like 100+ with stock gears. Anyone elses car do this? I'm going to take it into Ford, and I want to make sure all your cars don't do this. Specifically anyone v6's with 4.10 have you experienced this problem? Thank.

rygenstormlocke

I used to have 4.10's. Who installed your gears? Did they hook up a gauge to it to measure the pressure of the ring/pinion set? If not, they don't know gears. The first shop that installed mine didn't know how to do gears, and it whined so loud that I couldn't hear a thing, and my rear did vibrate a bit.

Stewart

The shop was the best installer in my area. They did a great job, no whine. I'm positive this was an issue before my gears were installed though, b/c the exact same vibration would happen upon decelleration when going 100 plus. Now it makes perfect sense since it's the same feeling at about 85, which the 4.10's would put the driveshaft spinning at the equivalent of what used to be 100, now going 100 with 4.10's would have been over 120 which I never went past before. So the harsh vibration probably was there but the vibration was definitely there before my gears went it, now I just notice it more since it happens at driveable speeds. Also I experience a simmilar vibration when passing through 1500 rpm's in any gear, and also when in 5th decellerating through 2500. It's very disconcerting but I'm 100% positive this happened before my gear install.

rygenstormlocke

Ok, good then. But now I have to wonder if you got the bum drive shaft issue that Afixer tore up on the dyno. I would look into that asap!

Stewart

Ya, definitely wont be going over 100 anytime soon, it sounds like the car is going to rip itself apart. I'm going to bring it into Ford and bitch about it, the way I see it there's no way they'll ever know I have new gears unless they drive it. But even if they do figure it out it should be fairly obvious it's no the gears that's causing the issue.

Stewart

And another thing, I noticed that in their flyer for the GT one of the plusses they were claiming to the solid rear axle is the ease of changing gears, so if Ford is promoting this I don't see how they could ever complain about gears being the cause of something that is drivetrain related.

Another thing I don't get is that from about 80-100 it only vibrates when decellerating but once you hit 100 it's like hitting a wall, and the vibration is terrible.

blackfoot

i was gonna say tranny issue till you said it did it in neutral.. it would only have to be a driveshaft issue now, when at stock it made the isseu at 100, well your driveshaft was spinning at X speed, now with the 410's your driveshaft will reach the same X speed at a lower KM/h

just upgrade to aluminum it would be your go fast fix

blackfoot

it being a solid driveshaft is irrelevant (sp?) to gear changing

Stewart

Ya I was worried about the transmission at first but after thinking about it I don't see anything else it would be other than the driveshaft, interestingly enough I was getting an oil leak a few weeks ago. Took it in, it was coming from my transmission, when I looked over the warranty repair it was listed as a replaced driveshaft assembly, who knows if this contributed but it happened before so it's bothersome. I don't really wanna have to put the money into a driveshaft, if everyone isn't having this problem I feel like this is an issue Ford should be able to fix.

blackfoot

if they replaced the drivesahft, its either an install error or defective part.. the guys are gonna hate to see a "come-back" but you have to put your foot down.. for all they know the shaft coulda been dinged in transport