Exhaust is dry, no coolant coming out there or into oil. Thanks, I am going to get a complete head from the Man in San Fran.
Last edited:
Bad vibrations
- Thread starter Stevehose
- Start date
tranny
shifted hitting your mount causing vibration. Engine mounts rubber look vertical and not twisted? More clearance at the radiator? Sometimes it doesn't take much.
You checked the power steering, did you make sure the lines aren't touching/ transmitting.
Clutch in, in gear, rev does what?
shifted hitting your mount causing vibration. Engine mounts rubber look vertical and not twisted? More clearance at the radiator? Sometimes it doesn't take much.
You checked the power steering, did you make sure the lines aren't touching/ transmitting.
Clutch in, in gear, rev does what?
Tranny mount: this is a posisbility, I had to shim the mount some more more in order to line up the output flange with the driveshaft flange so that, with the 2 flanges loosely bolted there was no wobble between the two. Then I bolted them tight. My concern is that this has shifted somehow but did not appear so when I checked. One of my plans is to take out the shims to see if this affects it either way. I had to put about 5 pieces of thin steel between the rubber and the tranny ear in order to line up the shaft. Judging from some other 5 speed install pics i have seen so have some others.
Any other tips on driveshaft alignment? The CSB needs to be same plane as the diff flange, then the tranny flange must be square to the front driveshaft flange?
I took the PS belt off so it's out of the equation.
Clutch in, in gear on highway the vibration goes away if I let the rpms drop to idle while coasting.
Any other tips on driveshaft alignment? The CSB needs to be same plane as the diff flange, then the tranny flange must be square to the front driveshaft flange?
I took the PS belt off so it's out of the equation.
Clutch in, in gear on highway the vibration goes away if I let the rpms drop to idle while coasting.
pmansson
Well-Known Member
Drive shafts
I have not read all the posts. Just wanted to mention them, or one of them.
I have not read all the posts. Just wanted to mention them, or one of them.
No to step on Steve's thread, but I have the same engine Steve has and was under the impression that a b35 head would decrease my compression ratio. If so, why do a b35 head?
Compression is 135-140 across all 6 which is what it alwys has been on my gauge.
123ignition distributor is functioning properly, and shows 3 amps for the coil.
So I will focus on the tranny mount geometry. Looking at the fan it appears as though the tranny and engine may be too high (top of fan closer to radiator than the bottom), but that's the only way I could get the driveshaft perfectly lined up.
Maybe I can look at lowering the CSB a little in order to not have to raise the tranny so much? This of course would be subject to keeping it in line with the diff...
Thanks for the ideas
123ignition distributor is functioning properly, and shows 3 amps for the coil.
So I will focus on the tranny mount geometry. Looking at the fan it appears as though the tranny and engine may be too high (top of fan closer to radiator than the bottom), but that's the only way I could get the driveshaft perfectly lined up.
Maybe I can look at lowering the CSB a little in order to not have to raise the tranny so much? This of course would be subject to keeping it in line with the diff...
Thanks for the ideas
Check your guibo to shift rod clearance
Does this happen in all gears?
Check all nuts at each end of driveshaft
Does this happen in all gears?
Check all nuts at each end of driveshaft
Pinion
angles are important. I assume BMW set up the geometry for a negative 3 to 5 degrees as most do. It sounds like you adjusted ( shimmed) the tranny mount to 0 degrees.
What happens is that the rear when it loads up changes its angle or geometry. The second thing to keep in mind is that the driveshaft is designed to take -up some angle and through the joints minimize vibrations. You could be out of range (shims) or under load out of range besides something touching or transmitting through the body.
The books don't mention this angle , but it's shown as lines going through the guibo in the cutaway. So it's not zero. There's a tolerance.
I can't remember where on the site, but at one time there was a jig made to check the driveline angles since the two shafts aren't equal. Maybe someone else remembers. I recall because I had a driveshaft that gave me problems and the car was converted from auto to manual long ago.
angles are important. I assume BMW set up the geometry for a negative 3 to 5 degrees as most do. It sounds like you adjusted ( shimmed) the tranny mount to 0 degrees.
What happens is that the rear when it loads up changes its angle or geometry. The second thing to keep in mind is that the driveshaft is designed to take -up some angle and through the joints minimize vibrations. You could be out of range (shims) or under load out of range besides something touching or transmitting through the body.
The books don't mention this angle , but it's shown as lines going through the guibo in the cutaway. So it's not zero. There's a tolerance.
I can't remember where on the site, but at one time there was a jig made to check the driveline angles since the two shafts aren't equal. Maybe someone else remembers. I recall because I had a driveshaft that gave me problems and the car was converted from auto to manual long ago.
Pinion part 2
I would disconnect the rear of the shaft and measure the angle at rest. You're going to have to use a protractor ( Sears, cheap) and then get a reference. Let's say-3, then shim the tranny to no more that -2 degrees to
get to what most vehicles are designed with.
I don't see shims on like Devinder's photos.
I also used a plumb bob on the floor, to check horizontal alignment of the engine, tranny, etc. all the way back. ( There was a home made jig- maybe the first fives site.) I do remember an adjustment at the center more than preload.
My motor had shifted. One mount ( the rubber) was visibly canted backwards to the firewall. I changed that one and shifted the motor back in position.
I know I had the same problem long ago on a vette motor swap into a Jag or Healy before I figured it out. ( back in the days before any of these were worth much.)
I would disconnect the rear of the shaft and measure the angle at rest. You're going to have to use a protractor ( Sears, cheap) and then get a reference. Let's say-3, then shim the tranny to no more that -2 degrees to
get to what most vehicles are designed with.
I don't see shims on like Devinder's photos.
I also used a plumb bob on the floor, to check horizontal alignment of the engine, tranny, etc. all the way back. ( There was a home made jig- maybe the first fives site.) I do remember an adjustment at the center more than preload.
My motor had shifted. One mount ( the rubber) was visibly canted backwards to the firewall. I changed that one and shifted the motor back in position.
I know I had the same problem long ago on a vette motor swap into a Jag or Healy before I figured it out. ( back in the days before any of these were worth much.)
Pinon #3
If you're feeling lucky.... try reindexing the drive shaft 180 degrees at the rear. Sometimes that has done it for some.
Did you check the driveshaft retaining nut at the slip joint? Mine was loose. i.e did you loose the preload?
HG- why you working so hard? The plugs are fine- tan. If you had coolant- one plug would be perfectly clean from the steam/ coolant. You checked the coolant. Pressurize the radiator to 7-9 lbs. If it holds for 30 minutes, then you're fine.
Are you seeing a spike at the temp gauge at start up, then it settles/ goes normal? Telltale sign of a head hot spot/ crack. Coolant leaks overnight, gets hot shows up at the gauge, t-stat opens and goes normal.
If you're feeling lucky.... try reindexing the drive shaft 180 degrees at the rear. Sometimes that has done it for some.
Did you check the driveshaft retaining nut at the slip joint? Mine was loose. i.e did you loose the preload?
HG- why you working so hard? The plugs are fine- tan. If you had coolant- one plug would be perfectly clean from the steam/ coolant. You checked the coolant. Pressurize the radiator to 7-9 lbs. If it holds for 30 minutes, then you're fine.
Are you seeing a spike at the temp gauge at start up, then it settles/ goes normal? Telltale sign of a head hot spot/ crack. Coolant leaks overnight, gets hot shows up at the gauge, t-stat opens and goes normal.
I feel a vibration sometimes but it's around 4000-4500 rpm.This makes sense that if not lined up could cause a vibration.I replaced 1 motor mount but after reading this thread I need to get the other one in and that one looks impossible to get at the nuts? Maybe someone can talk to Carl about this issue, I'm sure with all the 5speed installs his shop has done he would of seen this alignment problem?
Jerry:
Duly noted on the 180 switch
Nut tight w/preload
HG was done because I had everythng else off and did it "while in there" - mistake
I pressurized to 15psi and it has a very slow decline in pressure of 2 lbs after 10 min
I did an exhaust gas coolant check and it was negative, exhause pipe dry
no temp spikes, it is rock solid after driving or idling for a long time
The leak is going from coolant passage to crank case so the head is going to be replaced and I will send the original out to be checked and kept with the car. I am getting small steam puff from oil breather
Am looking into tranny mount and alignment as the next target
Thanks
Duly noted on the 180 switch
Nut tight w/preload
HG was done because I had everythng else off and did it "while in there" - mistake
I pressurized to 15psi and it has a very slow decline in pressure of 2 lbs after 10 min
I did an exhaust gas coolant check and it was negative, exhause pipe dry
no temp spikes, it is rock solid after driving or idling for a long time
The leak is going from coolant passage to crank case so the head is going to be replaced and I will send the original out to be checked and kept with the car. I am getting small steam puff from oil breather
Am looking into tranny mount and alignment as the next target
Thanks
Last edited:
driveshaft out of balance? I assume it was cut and re-balanced for the 5-speed install.
Update
I believe the solution has been found - the transmission was shimmed too high and was probably pressed against the tunnel. This was done so I could get the guibo and driveshaft flange perfectly flush with no wobble. It worked for a while but must have settled in and caused the symptoms.
Now that the tranny is lower it is now un-flush so I will need to lower the center bearing accordingly but I will need longer T-bolts than exists currently in order to do so which I have ordered then will need to fabricate a little to fit the slots in the body. Rob Siegel has a post on this very issue on the 2002faq. The fan is now equidistant from the radiator top and bottom.
So for now the revving in neutral vibration issue is gone. I will update once I do the csb adjustments and take it for a drive before closing the case for good.
Thanks for all your suggestions
I believe the solution has been found - the transmission was shimmed too high and was probably pressed against the tunnel. This was done so I could get the guibo and driveshaft flange perfectly flush with no wobble. It worked for a while but must have settled in and caused the symptoms.
Now that the tranny is lower it is now un-flush so I will need to lower the center bearing accordingly but I will need longer T-bolts than exists currently in order to do so which I have ordered then will need to fabricate a little to fit the slots in the body. Rob Siegel has a post on this very issue on the 2002faq. The fan is now equidistant from the radiator top and bottom.
So for now the revving in neutral vibration issue is gone. I will update once I do the csb adjustments and take it for a drive before closing the case for good.
Thanks for all your suggestions
Last edited:
Hi Steve, it would be great if you could post some pictures before and after the operation; what do you think the issue was that caused the misalignment in the first place? Just curious,when I did my first conversion there was allot of pushing and pulling to get things to fit but have not had any issues with vibration. Do you think the drive shaft was lengthened correctly? Maybe I should read Rob's post too
Thanks and it does look like you found your "gremlin".
Thanks and it does look like you found your "gremlin".