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Bell housing went on tonight, transmission should go in tomorrow. I can't seem to get the clutch fork to slide over the throw out bearing, but I didn't mess with it too long. I noticed the throw out bearing from McLeod is octagonal in shape, so maybe if I turn it a little the fork will slide on.
In the instructions from McLeod it mentioned to check the clearance between the floater plate and the clutch disc's using a .025 feeler gauge. Correct me if I am wrong, but once the clutch is assembled, and bolted in place, the disc, pressure plate, and flywheel should be pressed together. The only way to check the clearance would be to disengage the clutch by pulling on the throw out bearing. I'm nowhere near man enough to activate the throw out bearing by hand, and with the bell housing installed so you can use the slave cylinder to activate the clutch release, there is no way to insert a feeler gauge into the clutch assembly because the bell housing is in the way. The clutches are supposed to come pre-shimmed, ready to install, so hopefully mine will be OK.
Hydraulics are installed and bled, clutch fork is properly installed, hopefully I can get the transmission in tonight.
Is there a way to check the clutch for release? I installed the slave in the bell housing and had my sigificant other slowly press the clutch. The amount the clutch fork moved was very slight, so small that it was very hard to see with the naked eye. I think I might have some air left in the system. In retrospect, if the clutch had released with no alignment tool or input shaft installed, the clutch disk's would have fallen down, right?
I reverse bled the system, but I did it with the slave cylinder installed. Due to the position of the bleed valve, and the inlet line I can see how air would be trapped in the system if you were to reverse bleed it as I did. I am going to unbolt the slave tonight, and bleed the system again with the slave in a more bleed friendly orientation. Then, I am going to stick the alignement tool back into the clutch/pilot bearing, and then have the signifcant other press the clutch pedal. If the clutch releases I should be able to turn the alignement tool. Then, when she let's the clutch pedal return to the top of it's travel, the clutch should grab and the discs should be solid again. Atleast I hope that's how it goes.
I also broke the pivot ball lock when installing it. The ball lock should be torqued to 22 Ft. Lbs. As I was approaching the TQ spec, the small threaded end twisted off inside the pivot ball. The pivot ball is tight, so I am going to risk it and install the transmission. Hopefully the pivot ball doesn't back out. If my clutch engagement point starts to change at some point down the road, I'll know what it is, and can go from there.
The best tool for bleeding those hydraulics is a "Phoenix Tool." It pumps the fluid up from the bottom, is that what you meant by "reverse bled?"
The amount of movement is minimal... Think about it, the difference between a good clutch and a worn clutch is .020!!!!!(I think that's the number I measured)
I donno what to say about the pivot ball... I hope it stays...
Fist off, to do something like this in your garage everyone needs a friend like Tyler O.
I took Friday off from work to work on the car. Tyler and I started at about 930 AM. After some time on the phone (Thanks Bill Boudreaux) we found out that the clutch fork should be moving approximately 1/2 an inch. With the bell housing installed, the slave cylinder attached, and the system bled, Tyler pressed the pedal while I watched the fork and throw out bearing. The fork moved less than 1/8 of an inch. I assumed we had air in the system and went back to bleeding. After several different bleeding methods, we still could not get the clutch fork to move more than 1/8 of an inch. After 3-4 very frustrating hours we decided to pull the hydraulic system apart and start over. We removed the slave, and for grins I pushed in the clutch pedal, and activated the master cylinder. We expected fluid to spurt from the open end of the line under the car, but to our surprise, nothing happened. The master cylinder was not moving any fluid. I called Gene at McLeod, and after some trouble shooting, we decided to try adjusting the master cylinder rod. Initially, I had set the rod to the length of the stocker, perhaps a touch longer. Apparently, if the rod is too long, when it is pressed into the master cylinder it blocks one of the ports on the master and prevents fluid from moving. After shortening the rod we reinstalled the master and at long last, the fork moved the obligatory 1/2 inch.
As I mentioned earlier, I had broken the ball lock off in the ball stud. Fortunately, I was able to remove the broken piece of lock with a small easy out. After speaking with Bill at ZFdoc again (Geez, he is a great guy) I was told I could use a small bolt and a 1 inch washer. I had the bolt in my tool box, and found the washer at Home Depot. Bill also mentioned that the factory torque spec of 22 ft. lbs. for the the ball lock is entirely too much torque and you risk breaking the ball lock as I did. 8-10 ft. lbs. of torque is more suitable.
Alright, hydraulics are installed and working, time to install the transmission. If you're easily offended by swearing, you might want to skip this paragraph. The transmission is a mother ****er, and it has to be installed at the same time as the C-beam, which is also a mother ****er. When you combine the 2 mother ****ers, you end up with mother ****er to the second power. If you have access to a lift, it wouldn't be as bad, but on 22 inch jack stands in the garage, the install was tough to say the least. We were able to lift the transmission input shaft into the throw out bearing, then slowly bring the tail shaft and transmission end of the C-beam up at the same time with a jack. After lots of wiggling, swearing, and near death experiences the transmission was finally installed.
We buttoned up the C-beam, and installed the exhaust the next morning.
The maiden voyage went without incident, and the clutch is really not that much different than the stocker as far as pedal feel and ease of engagement. After about 80 miles of driving, the engagement point seemed to come to a rest about 2 inches from the top of the pedal travel, just like the stocker did. I put ~240 miles on the car yesterday, and was planning a track trip today, but the rain has killed that plan.
There is some added noise, but it's really only noticeable under moderate load between 2200 and 3000. In that range the gear noise is loud enough to interrupt a conversation between passenger and driver, but it is pretty rare. When climbing a hill with the cruise at 65 MPH for example. So far, the excessive gear noise is annoying, but entirely livable considering the clutch will withstand anything I throw at it. In 6th gear at 65-80 MPH the car sounds the same as it did with the dual mass. At idle, at stop lights and such, there is a louder gear kind of growling sound coming from the transmission, but it is less than 10% louder than the stock set-up. One thing I do like is there is no loud clanking from the transmission like there was with the dual mass. In stock form, at a light with the car in neutral, it would clank occasionally. A few seconds of quiet, then a clank or 2, more silence, then another clank, etc... That loud clanking hasn't made an appearance yet.
I ran the car to redline a few times, both in gear and in neutral and I have no vibration. The flywheel and clutch balance was perfect straight from McLeod. See the edit attached to my first post for the entire scoop on the balancing issue.
The girl friend drove the car last night, and other than the slightly stiffer pedal feel had no complaints. There is about a 2 inch area of pedal travel where the clutch slips, so as a daily driver the clutch is pretty great. All in all, I am really happy with it.
Sounds like you had some excitement with the hyrdaulics... it's one thing I am not looking forward to dealing with on mine.
Originally Posted by neat
As I mentioned earlier, I had broken the ball lock off in the ball stud. Fortunately, I was able to remove the broken piece of lock with a small easy out. After speaking with Bill at ZFdoc again (Geez, he is a great guy) I was told I could use a small bolt and a 1 inch washer. I had the bolt in my tool box, and found the washer at Home Depot. Bill also mentioned that the factory torque spec of 22 ft. lbs. for the the ball lock is entirely too much torque and you risk breaking the ball lock as I did. 8-10 ft. lbs. of torque is more suitable.
This is a good tip! I will add it to the C4 Tech FAQ!
Alright, hydraulics are installed and working, time to install the transmission. If you're easily offended by swearing, you might want to skip this paragraph. The transmission is a mother ****er, and it has to be installed at the same time as the C-beam, which is also a mother ****er. When you combine the 2 mother ****ers, you end up with mother ****er to the second power. If you have access to a lift, it wouldn't be as bad, but on 22 inch jack stands in the garage, the install was tough to say the least. We were able to lift the transmission input shaft into the throw out bearing, then slowly bring the tail shaft and transmission end of the C-beam up at the same time with a jack. After lots of wiggling, swearing, and near death experiences the transmission was finally installed.
Well... a tranny jack (and harbor freight has a nice one for about $50.00) is a godsend here. Also, the cbeam can be done after the transmission is installed... Another trick, as I read on the forum once before, is to put in some threaded rod on the bottom bolts of the bell housing to help guide the tranny up into place.
Sounds like you had some excitement with the hyrdaulics... it's one thing I am not looking forward to dealing with on mine.
Once the master was working properly, bleeding the system was a piece of cake. I did it with a Mighty-Vac brake bleeder. All I did was un-bolt the slave and let it hang down. If I twisted the slave a little, the line became the highest point on the slave cylinder, and theoretically the point that air should rise to. I stuck my Mighty-Vac on the bleed screw, opened the bleeder, and pumped fluid into the system. After I had the master 1/2-2/3 full, I closed the bleeder and all was well.
Well... a tranny jack (and harbor freight has a nice one for about $50.00) is a godsend here. Also, the cbeam can be done after the transmission is installed... Another trick, as I read on the forum once before, is to put in some threaded rod on the bottom bolts of the bell housing to help guide the tranny up into place.
It seems that I read the C-beam and transmission would not go in seperately. After doing the removal, I'd be surprised if you could R&R a C-beam with the transmission in place, but I'm not going to say it would be imposible. The threaded rod trick would only work if all you were installing were the transmission, not the C-beam. If it is possible to do the C-beam after the transmission is installed, the job would be much easier.
I have a transmission jack, but with the ZF6 on it, it would not roll under the car with the car on 22 inch stands. The combined height of the ZF6 and the jack was too great. We tried putting the ZF on the jack under the car, but a large floor jack worked better for our situation.
The maiden voyage went without incident, and the clutch is really not that much different than the stocker as far as pedal feel and ease of engagement. After about 80 miles of driving, the engagement point seemed to come to a rest about 2 inches from the top of the pedal travel, just like the stocker did. I put ~240 miles on the car yesterday, and was planning a track trip today, but the rain has killed that plan.
There is some added noise, but it's really only noticeable under moderate load between 2200 and 3000. In that range the gear noise is loud enough to interrupt a conversation between passenger and driver, but it is pretty rare. When climbing a hill with the cruise at 65 MPH for example. So far, the excessive gear noise is annoying, but entirely livable considering the clutch will withstand anything I throw at it. In 6th gear at 65-80 MPH the car sounds the same as it did with the dual mass. At idle, at stop lights and such, there is a louder gear kind of growling sound coming from the transmission, but it is less than 10% louder than the stock set-up. One thing I do like is there is no loud clanking from the transmission like there was with the dual mass. In stock form, at a light with the car in neutral, it would clank occasionally. A few seconds of quiet, then a clank or 2, more silence, then another clank, etc... That loud clanking hasn't made an appearance yet.
I ran the car to redline a few times, both in gear and in neutral and I have no vibration. The flywheel and clutch balance was perfect straight from McLeod. See the edit attached to my first post for the entire scoop on the balancing issue.
The girl friend drove the car last night, and other than the slightly stiffer pedal feel had no complaints. There is about a 2 inch area of pedal travel where the clutch slips, so as a daily driver the clutch is pretty great. All in all, I am really happy with it.
That's good news!!! Hopefully I'll do mine soon. Attached is my flywheel...looks like it has balancing weight...
That's exactly what mine looked like. When you pull your dual mass, check the holes around it's perimeter for hammered in weights. If you have no weight's pounded into your stocker, you should be good to go. If there are weight's in the stocker, off to the machine shop with you.
Bill Boudreau mentioned something about the LT4 cars being slightly different than the L98/LT1 cars, so you may want to shoot him an E-mail and ask what was different about them.
Unfortunately, I do not follow Nascar, and I am from Montana. I do not speak the dialect here, I do not know the secret Nascar password that identifies me as someone worth trying to help, and anytime I try to explain what I want done I am invariably, "A damn Yankee trying to tell him how to do his job."
I was reffered to a machine shop in Durham by Jeff Creech of Carolina Auto Masters, but they won't be open again until Monday. And it's 100 freakin' miles away. I can't believe I can't find someone local.
I was really hoping to get the car squared away this weekend, but I guess it will have to wait.
Thanks for the advice, and the explantion as to how to match balance was great. Maybe if I explain the procedure, I'll get somewhere.
I know this is an old thread but may help someone else from Montana so here ya go..........Hey fellers. Can y'all tell me what in the world "match balancing" is and how can I git er done to this here flywheel that goes on my Vette?........... That's all there is to it. I'm from WV but that should be close enough.
Last edited by GDMII; 03-15-2022 at 12:02 PM.
Reason: adding info
I know this is an old thread but may help someone else from Montana so here ya go..........Hey fellers. Can y'all tell me what in the world "match balancing" is and how can I git er done to this here flywheel that goes on my Vette?........... That's all there is to it. I'm from WV but that should be close enough.
The LT1 / LT4 made in the 1990s are externally balanced, some call it "GM balanced". The flywheel had, i think, 35 grams of weight on the back of the flywheel and the little holes. When I ordered a McLeod dual disk clutch for my car back in 2008 It was sent with a "GM Balance" with 35 grams bolted to the back. When you match balance you have the machine shop duplicate the IMBALANCE of the stock OEM flywheel from the factory to the new flywheel. That way the engine remains balanced once installed in the car.
aftermarket engine builders such as Golen will INTERNALLY balance the engine and weight is added to the crank. The flywheel in an internally balanced LT1/LT4 is neutral or zeroed, as in perfectly balanced.
If you remove the flywheel from your car, If factory original, you will have a flywheel like the one pictured below. Now. you can buy a GM Balanced / externally balanced flywheel. They sell them but if any of the holes are filled you need to take it to a machine shop to have them fill those holes with the same amount of weight found in your factory installed flywheel.
You can only blindly fill holes if going from OEM dual to new OEM dual. The issue is the aftermarket flywheels do NOT have the holes in the same locations. Otherwise you need to take it to a machine shop and tell them to match balance it.
in this photo. You can see the extra band of weight on one side and the holes. That weight is 35 grams if I recall correctly. If you machine that off the flywheel will be neutral.
GM had balancing issues with the LT1 engines and released a tech bullitin. The part numbert, at the time, for the pin weights is: 3890192
Now... If you replace your factory flywheel with another OEM Dual mass. You can use the following procedure to attempt to remove any new vibrations due to balancing issues. Only other option is to remove the engine and have it rebuilt and balanced.
This won't help to smooth out aftermarket flywheels... holes in the wrong spot and other issues.
My DM flywheel had 4 holes filled. Called a few machine shops about balance matching my Fidanza to the DM. All I heard was crickets. Then it I called Kim Barr Racing Engines and he knew exactly what I was talking about. Got it to him and an hour later it was done for $150. He had to take alot of weight out of the weight that that was installed by Fidanza to get it match the old. It's been a year and it drives good.
Advice is to call a race engine machine shop. Standard machine shops are not versed in some of the more detailed stuff of LTx engines from 25 years ago.
The LT1 / LT4 made in the 1990s are externally balanced, some call it "GM balanced". The flywheel had, i think, 35 grams of weight on the back of the flywheel and the little holes. When I ordered a McLeod dual disk clutch for my car back in 2008 It was sent with a "GM Balance" with 35 grams bolted to the back. When you match balance you have the machine shop duplicate the IMBALANCE of the stock OEM flywheel from the factory to the new flywheel. That way the engine remains balanced once installed in the car.
aftermarket engine builders such as Golen will INTERNALLY balance the engine and weight is added to the crank. The flywheel in an internally balanced LT1/LT4 is neutral or zeroed, as in perfectly balanced.
If you remove the flywheel from your car, If factory original, you will have a flywheel like the one pictured below. Now. you can buy a GM Balanced / externally balanced flywheel. They sell them but if any of the holes are filled you need to take it to a machine shop to have them fill those holes with the same amount of weight found in your factory installed flywheel.
You can only blindly fill holes if going from OEM dual to new OEM dual. The issue is the aftermarket flywheels do NOT have the holes in the same locations. Otherwise you need to take it to a machine shop and tell them to match balance it.
Actually,I was being funny incase someone else couldn't speak NASCAR. But you are spot on with your advice although 32 grams is what rings a bell with me. Good job getting that info out there.
The GM one piece seal SBC cranks are often referred to as internally balanced, but this is only true with regard to the front of the crank vibration damper, not the rear of the crank or flywheel. (late L98 and all LT1/4).
The flywheel balance spec is 23.4 oz/in. If the weight location is 4.5" (such as a Fidanza flywheel for example) then the weight added including hardware is 5.2 oz to a zero balanced flywheel.
GM has PN specs for fairly inexpensive flywheels, can be found in the manuals for the crate motors. Most balance shops like to match up the new flywheel to the old and it's not a terrible idea, but you have options.
I just went through extensive research on the forums and elsewhere along with discussions with people like Mike Norcia at RAM on this subject.
IMO - If you have a properly externally counter balanced GM spec *SMF* flywheel, you should not have to "match balance" that flywheel to the specific engine/original DMF. NOTE: It must be a high quality flywheel where you trust the aftermarket "GM spec" balance...perhaps this varies with manufacturer.
If you read the tech bulletin posted here closely, you will note that it applied to LT1 engines AND late 91 L98s. It describes it as an issue with the *redesigned* DMF that came out in late 91 with "changing balance at speed"....not a motor "defect" being corrected with the DMF.... If you were to replace your DMF with another DMF...if that "other" DMF was already on a running car with no vibration issues...I would leave it as is. NOS DMF yes I would match the balance weights.
I slapped my RAM counter balanced SMF directly on, and the engine is smoother than it ever was (granted I haven't gone on an actual test drive, but revving to 3k+ in neutral after warmup was smooth). Maybe I'll have egg on my face once I get it out there, but I know of another forum member here who did the exact same thing with a RAM SMF with no issues whatsoever.
Another datapoint for this is it only affected the DMFs... the automatic flexplates are all 100% identical and have no provision or procedure for "match balancing" to the engine. Yes it's a different amount of rotating mass/moment arm and the setup is less prone to this, but again it points to this being something amplified by the "mushy" DMFs.
Hate to post on this necrothread but it is very relevant and has the great info on the match balance procedure for the DMFs...that's something we must not lose!
05-01-2006, 10:42 PM
I'm from WV but that should be close enough.
