Problem Found, or Created During DS Install

[scramblr]

So for us ignorant of gears, what are we looking at and what's wrong with it? Guessing the "teeth" marks in the center is one of the outcomes of the problem?

 

[MrClean]

Question for y'all with the spydershaft: if you get up to ~105 and left off the gas and shift to neutral, do you get a reverberation as the speedo passes through 100-95-90? I seem to. It doesn't seem to do it under load, or at least I can't hear/feel it over the engine/tranny NVH, and when I say under load, I mean both ways...it doesn's seem to do it decelerating in gear (as much) as when it is in neutral....any similar experiences?

Can y'all try this and report back?

Should I start a new thread?

 

[scramblr]

Question for y'all with the spydershaft: if you get up to ~105 and left off the gas and shift to neutral, do you get a reverberation as the speedo passes through 100-95-90? I seem to. It doesn't seem to do it under load, or at least I can't hear/feel it over the engine/tranny NVH, and when I say under load, I mean both ways...it doesn's seem to do it decelerating in gear (as much) as when it is in neutral....any similar experiences?

Can y'all try this and report back?

Should I start a new thread?

No, I think you should post the same question in all the Spyder threads...Oh wait, you just did. LOL... Just messing with you Man. I replied in the other thread.

 

[MrClean]

No, I think you should post the same question in all the Spyder threads...Oh wait, you just did. LOL... Just messing with you Man. I replied in the other thread.

 

[Johnmichael]

So for us ignorant of gears, what are we looking at and what's wrong with it? Guessing the "teeth" marks in the center is one of the outcomes of the problem?

I'm not schooled in gears either, and I was waiting for Dave to come in but he's obviously tied up for the time being. Basically it's gear walk that caused those teeth marks.

Dave isn't sure what the main cause of the walk was, or if it was a combination of things. He said the install kit I supplied him with may have had some defective parts (which may be true). He also noticed that the preload (tuning torque on the flange ) on the pinion bearings was less than 5in/lbs and said it should be in the 20in/lb range. At first he thought the cause of that could be me tightening the pinion nut down too far, or the hard tapping I did to free the flange may have contributed, but when he reinstalled the flange/new pinion nut/bearings he too had to tap the flange off, and also had to torque the nut down far more than I ever could just to get the preload in the correct 20in/lb range so I don't think those could have caused it.

Here's what Dave did after seeing the damage. He looked over the parts and felt the carrier was fine even with the scoring, and that the teeth on pinion were not damaged enough thus were reusable. The bearings had some pitting/scoring so he changed those out. Before putting it back together he did the following:

Pinion bearing preload with new bearings: Ford spec: 16-29 in/lbs mine were set at 20 in/lbs. Ring gear backlash: Ford spec .008 to .015 in mine set at .011. Filled her up with Royal Purple.

He took the car for a spin up to 60, and all seemed fine. The problem is that the previous vibration started @ 65 and got ridiculous at 80 and above. So on my way home I was able to run it up to speed...the car felt fine for about 15 minutes but then the dreaded vibration returned.

At this point I'm thinking a whole new gear set is in order. The set I bought on eBay (new-but you never know) may have been defective, so this time it will be directly from FRPP. I've troubled Dave enough with this, so this time I will have a differential shop do the next install.

To be continued!

 

[scramblr]

I'm not schooled in gears either, and I was waiting for Dave to come in but he's obviously tied up for the time being. Basically it's gear walk that caused those teeth marks.

Dave isn't sure what the main cause of the walk was, or if it was a combination of things. He said the install kit I supplied him with may have had some defective parts (which may be true). He also noticed that the preload (tuning torque on the flange ) on the pinion bearings was less than 5in/lbs and said it should be in the 20in/lb range. At first he thought the cause of that could be me tightening the pinion nut down too far, or the hard tapping I did to free the flange may have contributed, but when he reinstalled the flange/new pinion nut/bearings he too had to tap the flange off, and also had to torque the nut down far more than I ever could just to get the preload in the correct 20in/lb range so I don't think those could have caused it.

Here's what Dave did after seeing the damage. He looked over the parts and felt the carrier was fine even with the scoring, and that the teeth on pinion were not damaged enough thus were reusable. The bearings had some pitting/scoring so he changed those out. Before putting it back together he did the following:

Pinion bearing preload with new bearings: Ford spec: 16-29 in/lbs mine were set at 20 in/lbs. Ring gear backlash: Ford spec .008 to .015 in mine set at .011. Filled her up with Royal Purple.

He took the car for a spin up to 60, and all seemed fine. The problem is that the previous vibration started @ 65 and got ridiculous at 80 and above. So on my way home I was able to run it up to speed...the car felt fine for about 15 minutes but then the dreaded vibration returned.

At this point I'm thinking a whole new gear set is in order. The set I bought on eBay (new-but you never know) may have been defective, so this time it will be directly from FRPP. I've troubled Dave enough with this, so this time I will have a differential shop do the next install.

To be continued!

Dave sounds like a hell of a guy, but the next shop may not be. May want to consider buying the gears through the shop, that way if anything is wrong, they're still responsible. Otherwise they may blame the parts which means you're forking over parts and labor all over again. Just a thought...

 

[MrClean]

Dave sounds like a hell of a guy, but the next shop may not be. May want to consider buying the gears through the shop, that way if anything is wrong, they're still responsible. Otherwise they may blame the parts which means you're forking over parts and labor all over again. Just a thought...

That's a great idea....they can get it from FRPP...even if it costs you $25-50 more..it sorta buys u insurance.

 

[Charlie Sheen]

Uh-oh, I'm having flashbacks!

 

[don_w]

May want to consider buying the gears through the shop, that way if anything is wrong, they're still responsible. Otherwise they may blame the parts which means you're forking over parts and labor all over again. Just a thought...

Zackly... I've been singing that song for a couple years. I've had two sets of gears installed, and I provided absolutely nothing to the installer either time.

 

[91Notch]

Ok I am finally here. First off I would like to say hello. My name is Dave and I am the owner/head mechanic for Genium Performance Automotive in Largo, FL. We mainly specialize in mustang performance.

I would like to thank Johnmichael and Scramblr for the very kind words.

And I still have no answer to this problem. As you stated Johnmichael when I took your rear end apart last night I found the the pinion bearing preload was way off but I was assuming it had something to do with you changing the pinion flange. I set that rear end up by the book as I set all my rear ends up. You looked over my shoulder learning last night and taking notes so you can attest to my attention to detail. I called another customer that I did a set of gears for on Saturday to make sure I wasn't having an equipment/tool failure (thinking my torque wrench might be out of calibration). He is reporting of no vibration at this time. For some reason it sounds like the pinion lost its pre load again. This time I have no explination. If you want when you get sometime leave the car with me and I will open it up again and go through everything again. There are a couple more measurements that can be taking with a rear end but of all the rear ends I have ever done it is very seldom to have to check these issues. Issues such has case run out etc. But I am gonna need sometime with it and I know its your daily driver so that might not be possible. It might actually be in the rear end housing it self. Starting to maybe think that cause you mentioned of a vibration since you bought the car, maybe the different gear ratio is amplifying the problem.

BTW the parts you brought me where new but I am un sure if they where FMS gears. You can tell when a gear has been used. It only takes about 10 miles to put a noticable wear pattern in a gear.

You know I value my customers and I will help you get to the bottom of this Johnmichael.

 

[Charlie Sheen]

Ok I am finally here...

Welcome to the forum!

Is it possible that that a pinion gear could slip back and then be torqued tooth edge-to-tooth edge of the ring gear?

 

[ZmanM3]

Welcome to the site 91NOTCH.

 

[spyder7724]

Question for y'all with the spydershaft: if you get up to ~105 and left off the gas and shift to neutral, do you get a reverberation as the speedo passes through 100-95-90? I seem to. It doesn't seem to do it under load, or at least I can't hear/feel it over the engine/tranny NVH, and when I say under load, I mean both ways...it doesn's seem to do it decelerating in gear (as much) as when it is in neutral....any similar experiences?

Can y'all try this and report back?

Should I start a new thread?

That really sounds like something in the differential. Problem is that the stock shafts were designed to hide the vibration problem Ford couldn't fix(or didn't want to spend the $ to resolve) so it could have been there since the car was new and you just never knew about it.
I've said this before but I really do think the problem in these cars is the stock limited slip carrier(posi unit). I had a heck of a time getting gears setup in my car. From my measurements and detective work I really think the ring gear is not centered. it's off just enough to cause the ring gear to move eccentrically and really throw things off.

 

[Johnmichael]

Dave sounds like a hell of a guy, but the next shop may not be. May want to consider buying the gears through the shop, that way if anything is wrong, they're still responsible. Otherwise they may blame the parts which means you're forking over parts and labor all over again. Just a thought...

Dave is a great guy, and he has treated me better than any other shop EVER has, which is why I don't want to put him through anymore of this.

Dave, I appreciate you showing up on here. It's funny you mention the housing because I recently read that housing flex can cause gear walk. Like I said when we first met, the vibration started between 2-500 miles after buying the car new.

Edit: Seeing Ron's comment about the carrier may just be the answer to my problem. What is your recommendation to replace the carrier, Ron.

 

[91Notch]

Dave is a great guy, and he has treated me better than any other shop EVER has, which is why I don't want to put him through anymore of this.

Dave, I appreciate you showing up on here. It's funny you mention the housing because I recently read that housing flex can cause gear walk. Like I said when we first met, the vibration started between 2-500 miles after buying the car new.

Edit: Seeing Ron's comment about the carrier may just be the answer to my problem. What is your recommendation to replace the carrier, Ron.

Don't worry about bothering me with this problem. This is what I do for a living. I actually really appreciate you as a customer. Your really understanding about all this and it makes working with you and enjoyable experiance. Like I said I am not only here to make a living I am here to make you guys happy also.

As for the carrier being the problem (which I am not saying it is or isnt) that still wouldnt correct case run out if the housing is out of wack. But if the carrier is the problem you may actually gain in this one. But it could get expensive. You have 31 spline axle stock in these years (all years prior had 28 spline) If you remember I showed you that Eaton locker diff sitting on my self at the shop. I love that unit I have put so much hp through those diffs I am actually surprised it took it. I try to use them in all my cars. I say you gain because the stock track lock diff from ford are not really the best. Now the down fall to the Eaton locker is when turning you can kinda hear it working back there. Its normal, so that diff probably isnt for you since your not shooting for the moon in the hp catagory. But there are other way better than stock diffs out there that would work good for you.

I keep reading the pinion angle issue. Maybe with your rear of the car lower and the front isnt and with the new DS maybe the pinion angle is off. I would check that before anything else IMO.

Again like I said your not bothering me with this. But I am not perfect, I might be missing something stupid. Maybe a second opinion wont hurt on this issue cause something weird might be going on. Trust me car guys talk alot. We call each other all the time saying Hey I got this car over here in my shop doing something weird, you run accross this issue yet? And dont ever let another mechanic tell you that they have never done that cause they are lying.

PS thanks to all the gave me a welcome to the board.

 

[MrClean]

PS thanks to all the gave me a welcome to the board.

Welcome Dave!

 

[onebadgsx]

i have the stock ds still with 4.10 gears insatlled, and i am getting this reverberation that mr.c talks about. i would like to get the spyder shaft but i wonder if this reverberation will get worse? this only happens at the same higher speeds above 85 mph with no load.

 

[scramblr]

It's going to be a crap shoot IMO. The plus is the aluminum will absorb some of the NVH vs the steel DS, but at the same time, you're getting rid of all the dampner Ford put in with the two piece. Something else that will help is having an adjustable UCA or LCAs to play with the pinion angle.

That being said, you should try and find out what's causing the vibrations before adding more mods which can make it harder to pin-point the problem.

 

[Johnmichael]

Don't worry about bothering me with this problem. This is what I do for a living. I actually really appreciate you as a customer. Your really understanding about all this and it makes working with you and enjoyable experiance. Like I said I am not only here to make a living I am here to make you guys happy also.

You rock, Dave! I wish more people in this business would emulate your practices.

As for the carrier being the problem (which I am not saying it is or isnt) that still wouldnt correct case run out if the housing is out of wack. But if the carrier is the problem you may actually gain in this one. But it could get expensive. You have 31 spline axle stock in these years (all years prior had 28 spline) If you remember I showed you that Eaton locker diff sitting on my self at the shop. I love that unit I have put so much hp through those diffs I am actually surprised it took it. I try to use them in all my cars. I say you gain because the stock track lock diff from ford are not really the best. Now the down fall to the Eaton locker is when turning you can kinda hear it working back there. Its normal, so that diff probably isnt for you since your not shooting for the moon in the hp catagory. But there are other way better than stock diffs out there that would work good for you.

I keep reading the pinion angle issue. Maybe with your rear of the car lower and the front isnt and with the new DS maybe the pinion angle is off. I would check that before anything else IMO.

I would love to have the pinion angle checked. I'm not sure if it can be adjusted without me having an adjustable upper control arm. I think we may be able to do it by putting the car on the lift, measure the PA on both the tranny and DS flange. If it's off, then we detach the DS from the pinion flange, and jack up the differential to the desired angle, then reattach. I'm not positive, but I think this would work.

Again like I said your not bothering me with this. But I am not perfect, I might be missing something stupid. Maybe a second opinion wont hurt on this issue cause something weird might be going on...

Thanks again for your awesome attitude and service, Dave. As for the next shop, I'm not sure where I will take the car. I still would like for some others to chime in with their advice before I try another gear install.

I did see on another thread here where Ron (Spyder Shaft CEO) mentioned crush sleeve issues causing similar problems. I believe you put a new crush sleeve in on Monday, so we can discount that as a cause.

 

[scramblr]

You rock, Dave! I wish more people in this business would emulate your practices.

I would love to have the pinion angle checked. I'm not sure if it can be adjusted without me having an adjustable upper control arm. I think we may be able to do it by putting the car on the lift, measure the PA on both the tranny and DS flange. If it's off, then we detach the DS from the pinion flange, and jack up the differential to the desired angle, then reattach. I'm not positive, but I think this would work.

Thanks again for your awesome attitude and service, Dave. As for the next shop, I'm not sure where I will take the car. I still would like for some others to chime in with their advice before I try another gear install.

I did see on another thread here where Ron (Spyder Shaft CEO) mentioned crush sleeve issues causing similar problems. I believe you put a new crush sleeve in on Monday, so we can discount that as a cause.

Not sure about other cars, but on the S197 you will need either an adj UCA or adj LCAs. You're actually rotating the differential and axle making the flange itself point up or down. So it's not the height of the differential that you're adjusting. The flange on the tranny should be at ~ -4*. You can't measure it unless you take off the DS from the flange since it should be measure from the face of the flange (same as the rear). However, you can measure the crank pulley and it should be at ~ +4*.