NV4500 swap clutch fun!

[shotty]

93 NV4500 into an M1008. I went with the bell housing, hydraulic linkage bracket, clutch, pressure plate, and slave cylinder as recommended from Advance Adapters here: https://www.advanceadapters.com/pro...95-gm-nv4500-5-speed-adapter-bellhousing-kit/

I started posting about my clutch issues over on this excellent nv4500 swap thread but it's time to start my own since I am using a different bell housing and

I got a LUK 6.5 flywheel which turns out is actually 1/4 inch thinner (and lighter) than the 6.2 flywheel. This explains why they are different part numbers despite the internet telling me they are interchangeable. While that may be true, they are also certainly different in some ways. I am having issues getting the clutch adjusted correctly with the above components. Too much preload on the throw out bearing and not enough travel to disengage the clutch.

I called AA today and this setup was designed for a 1" thick flywheel, which the 6.2 is but not the 6.5 I have installed. I was also told by the rep that I most likely need to shorten the pushrod. He seemed amazed they were still shipping the partially threaded pushrod in the hydraulic clutch linkage kit and not a piece of all thread. About to head out to the garage and install a new 6.2 flywheel then check pushrod length/engagement and cut it down 1/4 to 1/2 inch.

Oh I'm also going to adjust the pilot bearing depth. The instrauctions from AA said some applications might need to leave the pilot bearing exposed 3/16 of an inch instead of flushing it with the crank. After mounting my bellhousing and taking measurements I barely have any of the input shaft in the bearing. I'm going to pull the bearing out and put in a new one with 3/16 still exposed to capture more of the input shaft.

Once I get this all figured out I'll do up a thread with what I used and what ends up working...

 

[erasedhammer]

93 NV4500 into an M1008. I went with the bell housing, hydraulic linkage bracket, clutch, pressure plate, and slave cylinder as recommended from Advance Adapters here: https://www.advanceadapters.com/pro...95-gm-nv4500-5-speed-adapter-bellhousing-kit/

I started posting about my clutch issues over on this excellent nv4500 swap thread but it's time to start my own since I am using a different bell housing and

I got a LUK 6.5 flywheel which turns out is actually 1/4 inch thinner (and lighter) than the 6.2 flywheel. This explains why they are different part numbers despite the internet telling me they are interchangeable. While that may be true, they are also certainly different in some ways. I am having issues getting the clutch adjusted correctly with the above components. Too much preload on the throw out bearing and not enough travel to disengage the clutch.

I called AA today and this setup was designed for a 1" thick flywheel, which the 6.2 is but not the 6.5 I have installed. I was also told by the rep that I most likely need to shorten the pushrod. He seemed amazed they were still shipping the partially threaded pushrod in the hydraulic clutch linkage kit and not a piece of all thread. About to head out to the garage and install a new 6.2 flywheel then check pushrod length/engagement and cut it down 1/4 to 1/2 inch.

Oh I'm also going to adjust the pilot bearing depth. The instrauctions from AA said some applications might need to leave the pilot bearing exposed 3/16 of an inch instead of flushing it with the crank. After mounting my bellhousing and taking measurements I barely have any of the input shaft in the bearing. I'm going to pull the bearing out and put in a new one with 3/16 still exposed to capture more of the input shaft.

Once I get this all figured out I'll do up a thread with what I used and what ends up working...

Just a thought I didn't bring up before, do you have a 6.5 in your truck or just using a 6.5 flywheel?
I thought both flywheels are interchangeable?

 

[shotty]

Just a thought I didn't bring up before, do you have a 6.5 in your truck or just using a 6.5 flywheel?
I thought both flywheels are interchangeable?

I don't have a 6.5 (yet) but that's the eventual plan. There is a definite difference in flywheel thickness and weight despite what people say

 

[erasedhammer]

I don't have a 6.5 (yet) but that's the eventual plan. There is a definite difference in flywheel thickness and weight despite what people say

6.5 on the right?
In terms of interchangeability I was referring to diameter, bolt pattern, and tooth count.

 

[shotty]

Correct, 6.5 on the right. Everything you listed is all the same as far as I'm aware, they only seem to differ in weight and thickness. In the case of using am advance adapters bellhousing with a clutch setup designed for a 1 inch thick flywheel, I 5hink using the 6.2 flywheel is a key detail. I should know shortly once I get the new flywheel mounted and clutch installed. Fighting the pilot bearing right now...

 

[erasedhammer]

Correct, 6.5 on the right. Everything you listed is all the same as far as I'm aware, they only seem to differ in weight and thickness. In the case of using am advance adapters bellhousing with a clutch setup designed for a 1 inch thick flywheel, I 5hink using the 6.2 flywheel is a key detail. I should know shortly once I get the new flywheel mounted and clutch installed. Fighting the pilot bearing right now...

Yeah flywheel thickness seems to be the determining factor.
I wonder why the 6.5 needs a thinner flywheel? I assumed one could use the 6.2 flywheel on the 6.5?

Fighting the install of the pilot into the crank or the input shaft into the pilot?

 

[shotty]

Fighting removing the pilot bearing... I got a new one to install bit leave out 3/16 of an inch. Just got back from harbor freight with a slide hammer since a pilot bearing puller can't reach down into the crank

 

[shotty]

This pilot bearing was putting up quite the fight. Tried the grease/bread trick, no go. Tried a 2 jaw puller, no go. Ground down my cheap 3 jaw to puller to fit in there, it bent and broke. Got a 3 lb slide hammer, it just laughed. Started to cut into it but the shell is so thick I'd go bankrupt buying saw blades.

Decided to make a tool from some of the 2 inch steel I got to make a cross member spacer for the nv4500 swap. Cut a strip off it, drill three holes, tapped two of them for long bolts. Used the slide hammer bit to grab the bearing and an impact to drive the bolts on one side at a time. I actually ended up bolting an old flywheel on for the bolts to press on. Finally got the pilot bearing out. Glad to put the drill press to work.

 

[Mad Texan]

Certainly sorry to hear about your issues but glad you are getting to the bottom of it! I'll have to check the rod that came in my kit out of curiosity. The 6.2 flywheel is a beast for sure, I keep meaning to weigh it...

 

[erasedhammer]

Certainly sorry to hear about your issues but glad you are getting to the bottom of it! I'll have to check the rod that came in my kit out of curiosity. The 6.2 flywheel is a beast for sure, I keep meaning to weigh it...

Driving around you can definitely feel its impact. The thing really absorbs a ton of speed changes in the driveline/engine.

 

[shotty]

Clutch is sorted, mostly. I had to chop down the pushrod in the kit probably half an inch or so, maybe even more. Since the clutch is hydraulic there is of course no freeplay between the face of the throw out bearing and the pressure plate fingers because the slave cylinder takes up any slack. Knowing this, I set it so that the slave cylinder had just a bit of travel left in the pushrod before it bottomed out in the cylinder. So if I were to push on the clutch fork and drive the pushrod in the slave cylinder all the way in, there was just a bit of a gap between the throw out bearing and the pressure plate.

I also ditched one of the two jam nuts, effectively making it so I cant adjust the clutch position for now, but it was the only way to get things positioned right. If needed, I'll get some all thread and make my own fully threaded rod so I can set the jam nuts much lower as needed.

This ended up giving me a clutch engagement point at about 2/3 pedal travel. Good enough for now, we'll see how it plays out in the long run.

 

[shotty]

Fighting to get the crossmember on the frame now, going to slot the holes a bit to help with alignment.

 

[erasedhammer]

Fighting to get the crossmember on the frame now, going to slot the holes a bit to help with alignment.

Ha, had the same problem. I ended up putting a hydraulic jack and a piece of 2x4 inside the frame rails and physically pushing the rails further apart.

 

[shotty]

The frame rails being close are a problem too, but I'm slotting the holes in the cross member to allow it to slide back a half inch. I think the nv4500 setup is just a bit longer than the stock stuff, so I can't get the cross member and trans mounts to all align at the same time.

 

[erasedhammer]

The frame rails being close are a problem too, but I'm slotting the holes in the cross member to allow it to slide back a half inch. I think the nv4500 setup is just a bit longer than the stock stuff, so I can't get the cross member and trans mounts to all align at the same time.

I attached the trans mount spacer to the nv4500 first then bolted the cross member to the frame, then I drilled holes for the bottom two bolts. The holes in the trans spacer are not in the perfect middle of the spacer though, so I suppose it is a little of.

 

[shotty]

I attached the trans mount spacer to the nv4500 first then bolted the cross member to the frame, then I drilled holes for the bottom two bolts. The holes in the trans spacer are not in the perfect middle of the spacer though, so I suppose it is a little of.

That would probably be a better way to go about it, I measured and drilled my holes in the middle of the spacer but the new trans setup is a bit longer. Slotting the cross member holes worked though and eventually I'll get the right cross member so no spacer is needed. I also got new bolts that we're a tad longer and was able to use them to pull the cross member into position, no jack or prybar needed.

Got everything else sorted and took it for a drive, clutch is great. You really do need to shorten the rod a bunch for the center force clutch setup. I would suggest just snagging some all thread and using that to make a rod from the get go, then you can get the length adjusted right and only have to cut it once.

 

[erasedhammer]

That would probably be a better way to go about it, I measured and drilled my holes in the middle of the spacer but the new trans setup is a bit longer. Slotting the cross member holes worked though and eventually I'll get the right cross member so no spacer is needed. I also got new bolts that we're a tad longer and was able to use them to pull the cross member into position, no jack or prybar needed.

Got everything else sorted and took it for a drive, clutch is great. You really do need to shorten the rod a bunch for the center force clutch setup. I would suggest just snagging some all thread and using that to make a rod from the get go, then you can get the length adjusted right and only have to cut it once.

I originally tried to find the correct cross member (I believe a 700r4 W-style one), but couldn't find any.
Let me know if you end up finding one.

 

[Ilikemtb999]

Wow good info as I'm getting ready to order stuff for my swap soon. Expected to get the 6.2 flywheel and clutch anyways though.

 

[shotty]

Wow good info as I'm getting ready to order stuff for my swap soon. Expected to get the 6.2 flywheel and clutch anyways though.

Not sure how a 6.2 clutch will work with the AA bellhousing. I know @erasedhammer used a 6.5 clutch with the 6.2 flywheel and AA bellhousing.

 

[erasedhammer]

Not sure how a 6.2 clutch will work with the AA bellhousing. I know @erasedhammer used a 6.5 clutch with the 6.2 flywheel and AA bellhousing.

Actually my south bend clutch was listed as being for both 6.2 and 6.5.

"Truck Applications: Chevy/GMC 6.2L 1985-93, Chevy/GMC 6.5L 1994-01"