linux2
Junior Member
- Joined
- Mar 28, 2016
- Posts
- 4
- Reaction score
- 0
- Location
- Massachusetts
- First Name
- Will
- Truck Year
- 1990
- Truck Model
- Suburban 2500
- Engine Size
- 6.2
Back in October I bought myself a 1990 Diesel 2500 Suburban 4x4 which had a TH400 Automatic transmission in it. I've owned quite a few 6.2L diesel GM vehicles over the years and I can't stand the 3 speed auto behind it. I had owned another 2500 diesel suburban years ago that had a 700r4 behind it, which I actually liked quite a bit. Despite the negative comments I see about them I never ran into any issues the 40K miles I put on it.
While I was looking to convert my Suburban I was seeing quite a bit of modifications that would be needed to do this. So I started to look into a manual transmission swap. I'll cut the details short, but I now have a remanufactured NV3500 transmission installed in the Suburban.
Everything works great except for a "chatter" or "metallic" noise when the transmission is in neutral. I previously had a used NV3500 installed while I was seeing if everything would fit together. It also made the same ratting noise, but I figured it was something in the transmission. However, the remanufactured transmission makes the same noise. I'm wondering what I may have done wrong.
I put in a brand new flywheel, clutch, pressure plate, throwout bearing, clutch fork, and master and slave cylinder. I'm positive I installed the throwout bearing correctly on the fork. I'm wondering if anyone else has ever had similar issues with an NV3500.
As a note, as soon as you push the clutch in the noise stops. If you let the clutch up slowly, it starts making the noise as soon as the clutch engages with the engine. Again, this is only in neutral. When the vehicle is in gear there is no noticable noise, except if the engine RPMs are on the lower side, then you get a rather noisy gear chattering noise (perhaps maybe another clue as to what is wrong). The speedometer also moves when in neutral, so the input shaft in the transmission is rotating all the way through to the transfer case (where the speedo sensor is) and registering some small amount of movement.
I'd like to note that I didn't have many instructions when installing so I did place grease on the input shaft and on the bearing "guide" shaft (seemed to make sense to have that be lubricated). Otherwise it was a pretty straight forward install.
Any ideas on this? I had a chevy pickup (1500) that had an NV3500 in it stock and it made the exact same noise, but I figured it was the throwout bearing. Perhaps it wasn't.
While I was looking to convert my Suburban I was seeing quite a bit of modifications that would be needed to do this. So I started to look into a manual transmission swap. I'll cut the details short, but I now have a remanufactured NV3500 transmission installed in the Suburban.
Everything works great except for a "chatter" or "metallic" noise when the transmission is in neutral. I previously had a used NV3500 installed while I was seeing if everything would fit together. It also made the same ratting noise, but I figured it was something in the transmission. However, the remanufactured transmission makes the same noise. I'm wondering what I may have done wrong.
I put in a brand new flywheel, clutch, pressure plate, throwout bearing, clutch fork, and master and slave cylinder. I'm positive I installed the throwout bearing correctly on the fork. I'm wondering if anyone else has ever had similar issues with an NV3500.
As a note, as soon as you push the clutch in the noise stops. If you let the clutch up slowly, it starts making the noise as soon as the clutch engages with the engine. Again, this is only in neutral. When the vehicle is in gear there is no noticable noise, except if the engine RPMs are on the lower side, then you get a rather noisy gear chattering noise (perhaps maybe another clue as to what is wrong). The speedometer also moves when in neutral, so the input shaft in the transmission is rotating all the way through to the transfer case (where the speedo sensor is) and registering some small amount of movement.
I'd like to note that I didn't have many instructions when installing so I did place grease on the input shaft and on the bearing "guide" shaft (seemed to make sense to have that be lubricated). Otherwise it was a pretty straight forward install.
Any ideas on this? I had a chevy pickup (1500) that had an NV3500 in it stock and it made the exact same noise, but I figured it was the throwout bearing. Perhaps it wasn't.