High speed vibration

Yes try unhooking your driveshaft at one end and turning it 1 turn and
hooking it up at different ends. if this dont work try taking off your
rear end cover drain the oil and turn your wheels on half turn making
sure the wheel are not in the same position as last time. This might
require a person to hold one tire and the other to turn the other tire.
This is the cheap way first. The other way is to break down your trans
and put a rear seal in and check the drive shaft again because it still
could be off.
 >> Stay informed about: High speed vibration 

"Chris Bergquist" <chrisberg*NOSPAM*@pacbell.net> wrote in message
news:43E296B0.6C23A2EC@pacbell.net...
>I have a high speed vibration in 5th gear that starts to come in at
> about 2,000 RPM. This is the last "problem" in doing a T5 and rear end
> swap in a 68 Mustang fastback. I did the transmission first. I was
> able to use the original drive shaft. Everything was fine but the
> 2.70:1 rear end was way too tall so I swapped it out for a brand new set
> of 4.11:1 with a new Auburn limited slip. Let the vibrations begin!!!
>
> I pulled the drive shaft and had it checked... bent, twisted and out of
> balance, so I had a new one built. No change. Pulled it and had it
> rechecked and shorted it 1/2 ".
> Still no change.
>
> At or near 3,000 RPM in 4th gear no vibration. At or near 2,000 RPM in
> 5th the vibration starts.
>
> If I run the speed up in 5th past the point vibrations start and depress
> the clutch and coast it still vibrates.
>
> Any suggestions?
>
> Chris
> chrisb1erg*NOSPAM*@pacbell.net remove *NOSPAM*
>

I had a speed related vibration on an old 86 Ford Van I used to own.
Turned out it was the pinion angle. Maybe try that?!
 >> Stay informed about: High speed vibration 

I agree with .bob (nice to see your still around, it's been a ghost town
here!). It could be unbalanced tires, out of round tires if they've been
sitting for a long time. Could be pinion angle but I would save that for
last.

..boB wrote:

> Chris Bergquist wrote:
>> I have a high speed vibration in 5th gear that starts to come in at
>> about 2,000 RPM. This is the last "problem" in doing a T5 and rear end
>> swap in a 68 Mustang fastback. I did the transmission first. I was
>> able to use the original drive shaft. Everything was fine but the
>> 2.70:1 rear end was way too tall so I swapped it out for a brand new set
>> of 4.11:1 with a new Auburn limited slip. Let the vibrations begin!!!
>>
>> I pulled the drive shaft and had it checked... bent, twisted and out of
>> balance, so I had a new one built. No change. Pulled it and had it
>> rechecked and shorted it 1/2 ".
>> Still no change.
>>
>> At or near 3,000 RPM in 4th gear no vibration. At or near 2,000 RPM in
>> 5th the vibration starts.
>>
>> If I run the speed up in 5th past the point vibrations start and depress
>> the clutch and coast it still vibrates.
>>
>> Any suggestions?
>>
>> Chris
>> chrisb1erg*NOSPAM*@pacbell.net remove *NOSPAM*
>>
>
> Then it's not really rpm related, if it occurs when you coast. That
> means it's
> speed related.
> Check axles, brake rotors, tires, and wheels.
>
 >> Stay informed about: High speed vibration 

Thanks. All good suggestions. I'll go double check this weekend.

The vibration started AFTER I went from 2.73 to 4.11 gears. Vibration comes in
at 60 MPH (2000 RPM in 5th). Prior to gear change there was no vibration at
speeds in excess of 75 MPH. Since both the axles and tires RPM is the same
with either gear ration I have not spent any time there.

I'm convinced the problem is somewhere between the T5 output shaft (big $$$)
and the new gears.

Chris

Eugene Blanchard wrote:

> I agree with .bob (nice to see your still around, it's been a ghost town
> here!). It could be unbalanced tires, out of round tires if they've been
> sitting for a long time. Could be pinion angle but I would save that for
> last.
>
> .boB wrote:
>
> > Chris Bergquist wrote:
> >> I have a high speed vibration in 5th gear that starts to come in at
> >> about 2,000 RPM. This is the last "problem" in doing a T5 and rear end
> >> swap in a 68 Mustang fastback. I did the transmission first. I was
> >> able to use the original drive shaft. Everything was fine but the
> >> 2.70:1 rear end was way too tall so I swapped it out for a brand new set
> >> of 4.11:1 with a new Auburn limited slip. Let the vibrations begin!!!
> >>
> >> I pulled the drive shaft and had it checked... bent, twisted and out of
> >> balance, so I had a new one built. No change. Pulled it and had it
> >> rechecked and shorted it 1/2 ".
> >> Still no change.
> >>
> >> At or near 3,000 RPM in 4th gear no vibration. At or near 2,000 RPM in
> >> 5th the vibration starts.
> >>
> >> If I run the speed up in 5th past the point vibrations start and depress
> >> the clutch and coast it still vibrates.
> >>
> >> Any suggestions?
> >>
> >> Chris
> >> chrisb1erg*NOSPAM*@pacbell.net remove *NOSPAM*
> >>
> >
> > Then it's not really rpm related, if it occurs when you coast. That
> > means it's
> > speed related.
> > Check axles, brake rotors, tires, and wheels.
> >
 >> Stay informed about: High speed vibration 

No change in pinion angle but I'll check.

Chris

tranch wrote:

> "Chris Bergquist" <chrisberg*NOSPAM*@pacbell.net> wrote in message
> news:43E296B0.6C23A2EC@pacbell.net...
> >I have a high speed vibration in 5th gear that starts to come in at
> > about 2,000 RPM. This is the last "problem" in doing a T5 and rear end
> > swap in a 68 Mustang fastback. I did the transmission first. I was
> > able to use the original drive shaft. Everything was fine but the
> > 2.70:1 rear end was way too tall so I swapped it out for a brand new set
> > of 4.11:1 with a new Auburn limited slip. Let the vibrations begin!!!
> >
> > I pulled the drive shaft and had it checked... bent, twisted and out of
> > balance, so I had a new one built. No change. Pulled it and had it
> > rechecked and shorted it 1/2 ".
> > Still no change.
> >
> > At or near 3,000 RPM in 4th gear no vibration. At or near 2,000 RPM in
> > 5th the vibration starts.
> >
> > If I run the speed up in 5th past the point vibrations start and depress
> > the clutch and coast it still vibrates.
> >
> > Any suggestions?
> >
> > Chris
> > chrisb1erg*NOSPAM*@pacbell.net remove *NOSPAM*
> >
>
> I had a speed related vibration on an old 86 Ford Van I used to own.
> Turned out it was the pinion angle. Maybe try that?!
 >> Stay informed about: High speed vibration 

An even dozen counting the monkeys!!! Let me see if I can address them one by
one:

Keep YerSpam wrote:

>
> I'll still give you an Even Dozen things to cheak!
>
> Like:
> 1. You lost or broke a wheel weight changing things around.

Could be. Getting tires balanced today

>
> 2. Your tires are out of round from normal wear.

New tires. less than 1,000 miles, BF TAs

>
> 3. Your tires are out of round from sitting/storage.

It's my everyday driver. Gets out almost every day.

>
> 4. You have a damaged belt in a tire from smacking a pothole or curb
> causing it to be out of round or warped.

New tires, but possible

>
> 5. Out of round brake drum/rotor (rust can throw off balance, but it
> gotta ba pretty bad to do that).

Less than 1,000 on complete brake replacement, front and back.

>
> 6. You have a bent wheel rim.

New wheels, but possible. I'll ask them to be checked when I get them
balanced.

>
>
> Try swapping your front tires to the rear & rear tires to the front. If
> the vibration moves to the steering wheel, you've found your problem.
>

I'll do that when I get them balanced

>
> Other things to check:
> 1. You put a nice looking axle with a twisted axle shaft in your car
> taken from another car driven by someone liked to do burnouts &/or
> brake-stands in. Those are very expensive jokes.

Maybe, but why do I have a vibration now at 60 MPH that I didn't have before I
replaced the 2.73 for 4.11?

>
> 2. Your axles look straight, but the hubs aren't geometrically true tothe
> shaft. Accidents of some kind are likely the cause of this one.

Same response as #1
3. Your U-Joints are going out and letting your good drive shaft sit outfox
round during rotation.
Yoke and U-Joints were replaced with new drive shaft

> 4. Your wheel studs are either loose or worn and your rims aren't really
> sitting exactly where they should be.

I'll check when we balance the tires later today.

>
> 5. One of your wheel bearings is going out.

New, front (last summer) and rear (when I changed the gears)

>
> 6. There are monkeys living in your trunk who jump around a lot when
> road noise scares them at freeway speeds.

This is the most likely. Any suggestions where they hide when the car is
stopped. can't check for them at 70 MPH......

>
>
> OK, Maybe not the last one so much.
>
> Cheers,
> - Jeff G

Thanks again for all your suggestions.

Chris
 >> Stay informed about: High speed vibration 

Eugene Blanchard wrote:

> I agree with .bob (nice to see your still around, it's been a ghost town
> here!). >

Nice to "see" you, too. It has been awfull quiet around here, hasn't it?

--
..boB
On Order: 2006 FXDI, Red.
1997 HD FXDWG - Turbocharged Stolen 11/26/05 in Denver
1HD1GEL10VY3200010 CO License J5822Z
2001 Dodge Dakota QC 5.9/4x4/3.92
1966 Mustang Coupe - Daily Driver
1965 FFR Cobra - 427W EFI, Damn Fast.
 >> Stay informed about: High speed vibration 

I've joined a couple of yahoo groups which are much more active: Kustoms and
Sleds group and the Pontiacs-1950s group. There's about 400 members in the
latter. Also the Canadian Pontiac group. Lots of tech expertise there and
no spam and they're free.

..boB wrote:

> Eugene Blanchard wrote:
>
>> I agree with .bob (nice to see your still around, it's been a ghost town
>> here!). >
>
> Nice to "see" you, too. It has been awfull quiet around here, hasn't
> it?
>
 >> Stay informed about: High speed vibration 

You can raise the rear of the vehicle, put it on jack-stands and blocks,
block the fronts, chain it down etc (or lift the whole car off)... then
remove the rear wheels and start it up and put it in gear. It's best and
safest if you let the rear hang and block/support the frame.

Take it up to speed very slowly and see/feel what you can. A lot of
driveline vibrations can be found that way. However, don't try this trick
with the tires/wheels on and keep everyone else clear. If you have drum
rears, put some lug nuts on to make sure the drums stay attached if they
aren't otherwise held to the axle. (might need some spacers to do that too)


"Eugene Blanchard" <blanchae DeleteThis @telus.net> wrote in message
news:aZWEf.250623$OU5.73376@clgrps13...
> I've joined a couple of yahoo groups which are much more active: Kustoms
> and
> Sleds group and the Pontiacs-1950s group. There's about 400 members in the
> latter. Also the Canadian Pontiac group. Lots of tech expertise there and
> no spam and they're free.
>
> .boB wrote:
>
>> Eugene Blanchard wrote:
>>
>>> I agree with .bob (nice to see your still around, it's been a ghost town
>>> here!). >
>>
>> Nice to "see" you, too. It has been awfull quiet around here, hasn't
>> it?
>>
>
 >> Stay informed about: High speed vibration 

How a bout UJOINT?
 >> Stay informed about: High speed vibration 

Chris Bergquist wrote:

> I have a high speed vibration in 5th gear that starts to come in at
> about 2,000 RPM. This is the last "problem" in doing a T5 and rear end
> swap in a 68 Mustang fastback. I did the transmission first. I was
> able to use the original drive shaft. Everything was fine but the
> 2.70:1 rear end was way too tall so I swapped it out for a brand new set
> of 4.11:1 with a new Auburn limited slip. Let the vibrations begin!!!
>
> I pulled the drive shaft and had it checked... bent, twisted and out of
> balance, so I had a new one built. No change. Pulled it and had it
> rechecked and shorted it 1/2 ".
> Still no change.
>
> At or near 3,000 RPM in 4th gear no vibration. At or near 2,000 RPM in
> 5th the vibration starts.
>
> If I run the speed up in 5th past the point vibrations start and depress
> the clutch and coast it still vibrates.
>
> Any suggestions?
>
> Chris
> chrisb1erg*NOSPAM*@pacbell.net remove *NOSPAM*

Okay, got the tires/wheels rebalanced. Checked for out of round or bent
wheel. Rotated front to back. No change.

Anyone know what the pinion angle should be?

I have a line on used T5. I'm thinking of just spending the $300 and see if
that makes it go away. I can always resell the T5 after I do the swap.

Chris
 >> Stay informed about: High speed vibration