: GForce driveshaft



wifesv
09-19-11, 12:07 AM
Anybody have one installed? just looking to see how much you like it? how many miles you have on it? any problems?

I have about 200 miles on mine and just started to get a bad low frequency vibration from drivetrain area, at 35+MPH. i will be calling them monday with some questions. didnt have this problem before install. might not be the problem, but its the last new part.

90max
09-19-11, 08:40 AM
i'm so glad someone else started this before i did. i honestly HATE my car right now. the reason for the vibration is the "stub" i have called g force and they said the person who engineered the stub didn't torque it down correctly or its defective. i am also having other issues with it. i truly wish i was NOTIFIED about this before spending 5500$ i could have waited till it was done right. (maybe g force can come in here and explain it correctly if i have a lack of knowledge) but so far they have been very nice in the customer service department and i have nothing bad to say as long as in 3 weeks i recieve a new stub.

lollygagger8
09-19-11, 08:55 AM
I have one installed on my 9" rear end, and I get a little vibration at 60-70mph. My tires are shot so I was going to wait til I melt them and get my new ones installed before I blame the driveshaft.

That said, I didn't have the vibes until I put the new rear end in. :hmm:

AngryHog
09-19-11, 12:04 PM
I have one installed and have put several hundred miles on it. I get bad vibration from 35-55 mph. At first, I thought I knew what it might be. When I got mine, it came with some bolt problems. Namely, the 3 Allen bolts for the front end had one that was 10mm shorter than the other two. I thought this might be because of some kind of clearance issue, but that wasn't the case when I installed it. The bolts stop just short of coming out the other end, so having one even shorter was pointless. Plus, it came with those nuts with poly in them that only fit these bolts...and like I said, they don't protrude out so what was the point of those nuts? I was in a pinch at the time, so I installed with the one shorter bolt. When I first noticed the vibration (which was right away), I went on a mission to get another bolt in the right length, just in case this was causing a balancing problem. Well, that is the most difficult bolt I have ever had to replace in my life (it's a 1.50mm pitch, where most bolts of this size are 1.75mm...and to a lessor degree, 1.25mm). Spent half a day driving to many places only to be able to find it in longer lengths (at Ace hardware) that I would have to cut down. So I did. That was a chore as those bolts are pretty stout. I wasn't able to cut it so I had to grind it on my bench grinder for a good hour+. Once I reinstalled that bolt, I noticed the longer original ones seemed like they might actually be a fraction of a mm too long and possibly cause the adapter plate to not quite sit right. So I pulled both those out and grinded a smidge off the ends of them to make sure that wasn't the case. Put it all back together and the vibration is still there (although maybe 20% less annoying). It's not enough that I feel the car is going to shake apart, but it has me concerned for higher speeds. I haven't had the car over 95 since then.

Oh, and as a side note, while I'm talking about the bolts, the 6 sent with the kit for the rear end were the absolute wrong threading and useless. I ended up reusing the stock ones which are significantly longer and stick out the back, but there is nothing to snag on back there so I'm not too worried about it.

Overall, the adapters and driveshaft fit together on the car perfectly. But whoever selected the bolts to bundle with it needs an updated prescription on their glasses.

-Angryhog™

P.S. I'm running a stock rear end, just in case anyone is wondering.

wifesv
09-19-11, 01:52 PM
Wow...now i am glad i started this. i was really hesitant at first but glad i did. well let me first say i am haveing the same problems with the bolts as you AngryHog. I have been under my car 4 times in the first 200 miles and found 5 bolts comin loose. but also the front ones you talked about are way to short, maybe 3 threads only holding the front adapter to the trans. Also have found 2 really loose on the rear, driveshaft to adapter side. i dont have a grinder so dont really know what to do about the bolts as of now.
90Max is it at all possible we can talk by phone? i just got done talking to Gforce and they said they have not heard of this problem at all. the rear stub you are talking about is this attached to the back of the driveshaft? Do you have the whole 9 inch rear end kit or the stock rearend. i would like to talk to you and see who you talked to, when i called Gforce they refered me to PST who makes the driveshaft. its seems like I am getting the run around already. PSt said it was also the first they heard of this issue. I have the stock rear end. I am now sure its an issue with the drive shaft, if the drive shaft and adapter pates where not balanced together could this be an issue. Also why was my car fine the first 200 odd miles? did both of you have the same issue the car was good for awhile then started doing this?
I really think we all need to talk abotu this as much as possible until we figure it out and if we have an issue with manurfacturing from either company they need to fix it.

GFORCE1320
09-19-11, 05:50 PM
Guys, we can send new hardware (bolts) that are the correct length. I wish you would of just called when you discovered there was a problem with the hardware and we could of overnighted you the new hardware.
The guy we had picking our hardware kits got canned for this very reason..

We are not giving anyone the run around, if it is the driveshaft then we can have PST check it for ballance and if it is off then they can fix it. There really isnt anything else we can do.

As far as the bolts coming loose, I would recommend putting them in with loctite.

Thanks
Chris

GFORCE1320
09-19-11, 05:52 PM
i'm so glad someone else started this before i did. i honestly HATE my car right now. the reason for the vibration is the "stub" i have called g force and they said the person who engineered the stub didn't torque it down correctly or its defective. i am also having other issues with it. i truly wish i was NOTIFIED about this before spending 5500$ i could have waited till it was done right. (maybe g force can come in here and explain it correctly if i have a lack of knowledge) but so far they have been very nice in the customer service department and i have nothing bad to say as long as in 3 weeks i recieve a new stub.

You have a 9" kit, your mechanic and I talked on the phone about what could possibly be the problem and we are not real sure. We are going to send a new set of inner axle stubs to see if that is it, if that isnt it then it could possible the Strange posi unit. We'll get it figured out, just have to be patient.

Thanks
Chris

yooper
09-19-11, 11:11 PM
:v: subscribed

90max
09-20-11, 07:51 AM
You have a 9" kit, your mechanic and I talked on the phone about what could possibly be the problem and we are not real sure. We are going to send a new set of inner axle stubs to see if that is it, if that isnt it then it could possible the Strange posi unit. We'll get it figured out, just have to be patient.

Thanks
Chris

like i said b4 i hate my car not g force because i know things happen. as far as speaking to you guys i really have no worries that you will jerk me i truly hope the stubs are the issue and this gets fixed it sucks owning 3 cars and all 3 go down at the sametime i'm borrowing cars for 3 weeks till the new stubs come in or at least we figure out the issue i hate pushing ppl to pump things out. i know perfection takes time

but reguardless i'll be calling you guys during the week again just to confirm everything you told my mechanic due to me being the owner and the warranty being under my name i need 2 hear these things for myself.

wcryan
09-25-11, 03:15 PM
any updates?

wifesv
10-16-11, 09:53 PM
So i Was able to figure this out. sorry it took so long. Well the vibration was coming from the aft adapter plate being loose on the rear diff. I Didnt find this out the first time i went under the car because i had it in my garage on ramps. Well when i put it on a lift i was able to see the 6 bolts that hold the aft adapter plate on where all backing out. But the driveshaft bolts up over top of them so they would never fall out or appear loose. I had to grab the back of the drive shaft and wiggle it. it had about a quarter inch of free play and at 35MPH thats a lot of vibe. So i remembered in Angryhogs post about the aft bolts being wrong. I pulled the driveshaft off the adapter plate and took the plate off. Then put the 6 bolts back in and just like angryHog the thread sizes where all to small. with the bolts down all the way they would still wiggle. But with the adapter plate in you Can torque down the bolts with the apperance of being tight. But in a few days of driving they become loose. The kicker is I already tossed my stock bolts in the trash(when i installed the DS). So i had to resort to another method, us loctite like liquid shim. i put so much loctite on the bolts, and let them dry. I have been driving it for about 150 miles and no issues yet but i definately need new bolts from QForce. So its a Good thing Jeramy at Gforce said he was going to send my new bolts out ASAP! when i called with this issue. Well that was 3 weeks ago.........So here i go again waiting on GForce to send out bolts after i talked to them on the phone and had a verbal aggrement they would send out new bolts the next buisness day. i even gave them my order number for the DS and he said back "yup there you are still in our system." So whats the hold up GForce When do i get my new bolts that fit?
I have one installed and have put several hundred miles on it. I get bad vibration from 35-55 mph. At first, I thought I knew what it might be. When I got mine, it came with some bolt problems. Namely, the 3 Allen bolts for the front end had one that was 10mm shorter than the other two. I thought this might be because of some kind of clearance issue, but that wasn't the case when I installed it. The bolts stop just short of coming out the other end, so having one even shorter was pointless. Plus, it came with those nuts with poly in them that only fit these bolts...and like I said, they don't protrude out so what was the point of those nuts? I was in a pinch at the time, so I installed with the one shorter bolt. When I first noticed the vibration (which was right away), I went on a mission to get another bolt in the right length, just in case this was causing a balancing problem. Well, that is the most difficult bolt I have ever had to replace in my life (it's a 1.50mm pitch, where most bolts of this size are 1.75mm...and to a lessor degree, 1.25mm). Spent half a day driving to many places only to be able to find it in longer lengths (at Ace hardware) that I would have to cut down. So I did. That was a chore as those bolts are pretty stout. I wasn't able to cut it so I had to grind it on my bench grinder for a good hour+. Once I reinstalled that bolt, I noticed the longer original ones seemed like they might actually be a fraction of a mm too long and possibly cause the adapter plate to not quite sit right. So I pulled both those out and grinded a smidge off the ends of them to make sure that wasn't the case. Put it all back together and the vibration is still there (although maybe 20% less annoying). It's not enough that I feel the car is going to shake apart, but it has me concerned for higher speeds. I haven't had the car over 95 since then.

Oh, and as a side note, while I'm talking about the bolts, the 6 sent with the kit for the rear end were the absolute wrong threading and useless. I ended up reusing the stock ones which are significantly longer and stick out the back, but there is nothing to snag on back there so I'm not too worried about it.

Overall, the adapters and driveshaft fit together on the car perfectly. But whoever selected the bolts to bundle with it needs an updated prescription on their glasses.

-Angryhog™

P.S. I'm running a stock rear end, just in case anyone is wondering.

GFORCE1320
10-17-11, 12:48 PM
Could you kindly give us a call so we can get your hardware out to you, PM's still not working..
I got to the bottom of why your hardware kit never got to you. grrr..

Thanks
Chris

Mat347
12-11-12, 07:54 PM
An old post, but I just got this shaft installed and have developed the same issue. A really nasty resonant vibration from upper 30s to mid 40s is the worst spot. I Emailed G-force about a week ago with no response.

I used loctite when installing on all bolts so none were coming out. All the bolts were the same and are of proper length.
I don't recall having any installation instructions that came with it, perhaps I've got the drive shaft indexed incorrectly. I lined up the marks, but have discovered that some, two-piece, DSs are meant to be a few teeth "off".

Could someone let me know if the shafts should be installed lined up? It's getting to the point of being undriveable and with it being my daily, I've got to have it for work.

I've disconnected the DS from the front mount and made sure it wasn't something in my transmission causing it. It's got to be something with the shaft as it's at that frequency and independent from RPM/gear.

Thanks for any help!

GFORCE1320
12-12-12, 01:02 PM
An old post, but I just got this shaft installed and have developed the same issue. A really nasty resonant vibration from upper 30s to mid 40s is the worst spot. I Emailed G-force about a week ago with no response.

I used loctite when installing on all bolts so none were coming out. All the bolts were the same and are of proper length.
I don't recall having any installation instructions that came with it, perhaps I've got the drive shaft indexed incorrectly. I lined up the marks, but have discovered that some, two-piece, DSs are meant to be a few teeth "off".

Could someone let me know if the shafts should be installed lined up? It's getting to the point of being undriveable and with it being my daily, I've got to have it for work.

I've disconnected the DS from the front mount and made sure it wasn't something in my transmission causing it. It's got to be something with the shaft as it's at that frequency and independent from RPM/gear.

Thanks for any help!

Hey Mat,

I searched through our email and I can't find a missed email. I am sorry if it slipped between Chris and myself.

If you want to send it to PST, I will have them check it out as soon as possible for you. Also I can send you a new drive shaft adapter, we have two options now for the front. Please give us a call and we will make sure you get taken care of asap.

Thanks,
Casey

Mat347
01-07-13, 12:39 AM
I'll get with you ASAP. I've been fiddling with adding bushings to the center bearing which seems to have helped it some. It's not silky smooth though. I'm curious, what are the two options for the front?(I'm sure others may want to know as well). Lastly, as stated above, this is my daily driver. Is there anyway to minimize downtime? A cross-ship of sorts perhaps?
Thanks again,
Mat

Slow Lane Blues
01-08-13, 01:39 PM
I have been having the same issue since I installed my 9" kit. Had the Driveshaft balanced, got another one to see if it would help. Still a vibration but mine is a higher speeds, and no way I can take it over 90 MPH anymore. Also it was my DD until the vibration. now it is just horrible and I cant stand to drive the car so it just sits.

Has anyone figured out how to stop this vibration?

FoD
01-08-13, 01:56 PM
Which driveshaft(s) are being discussed here? I Just ordered one, the 2-piece replacement, stock diff. Are any of the problem ones the 1-piece? Are the 9" kits driveshafts different than the 2-piece listed on their site?

GFORCE1320
01-08-13, 02:34 PM
Which driveshaft(s) are being discussed here? I Just ordered one, the 2-piece replacement, stock diff. Are any of the problem ones the 1-piece? Are the 9" kits driveshafts different than the 2-piece listed on their site?

He has a very specif vibration that we are trying to isolate, might be his front adapter.

It doesn't apply to any other shafts we have as we just dont have many problems with them.

Slow Lane Blues
01-08-13, 04:02 PM
Despite having a vibration and working to find it, I cant say anything bad about G-Force staff and customer service, they even offer to overnight me the parts to work on finding the problem. THere are two different lengths for the two piece from what I understand, and the 9" kit is just a bit shorter, also a different adapter on the back for pinion conection.

FoD
01-08-13, 04:08 PM
Thanks GForce and Slow Lane for clarifying. Good to know. I figured the 9" DS would be shorter, but wasn't sure. I'm glad to hear your Customer Service with GForce has been a positive. Good luck with your DS.