noisy Mitchell transmission.
- Thread starter GASSERBOB
- Start date
GASSERBOB, any update? I too have a Mitchell Synchromesh. I installed it last year and it was noisy right away, especially in 2nd gear. I called and spoke to a gentleman that suggested that I drain out the GL5 rated 80W-140 and install 50% GL5 rated 80w-140 with 50% STP. I never did that. I figured I see if the trans noise got better over time. Now, a year later the noise recently has gotten worse. I'm planning on calling Mitchell to see if they still stand by the 50/50 recommendation or maybe recommend something else. The noise has gone from a loud wine to now a loud tinny metal sound when you first enter 2nd, gets better just before you shift to third. I will share my experience once its fixed.
Y-Blockhead
Well-known member
Late response Joel, I just saw your post... IF I had been able to talk to someone I'm sure the outcome would more than likely been different. But you see you missed the point. I could not get ahold of anyone to talk to.
Art Newland
Well-known member
I've got about 100 miles on my synchronized transmission now. It was a little noisier than I expected, but after about 30 miles it started quieting down and now sounds like any other Model A transmission. I'm sure it needed a little break-in.
daveymc29
Well-known member
Mitchell does not run the new transmissions in. They will get quieter really quickly in most cases if driven with oil in them and some common sense used. Most any new gears will be noisy when first engaged, but I will wager that even yours with 50 miles on them are quieter than when you started. My hearing isn't all that good, so I have never heard my ******, The Mitchell. If it is still noisy after 100 miles I'd call Steve Mitchell.
Hi, I'm getting back to everyone on the noise issue with my Mitchell transmission.
I removed and dis-mantled the Mitchell transmission and discovered defective roller bearings. The same type of problem that has occurred on newly manufactured rear wheel roller bearings is now occurring on transmission roller bearings. They are manufactured very poorly. These bearings have been sold by at least one major Model A parts vendor and installed in both original & Mitchell transmissions. The bearings used in both transmissions are the same part number. In some cases the end plates seem to be soft and the rollers eat through. In other cases the bearings are warped and don't spin properly. Also, there appears to be a design change in the rollers form NOS to newly manufactured. The old style bearings had an axle at each end of the bearing that fit into a hole in the end plates. The newly styled bearings have hollowed out ends on the rollers that fit into small round protrusions on the end plate. See the attached photos.
Mitchell has been excellent with their response & support. They sent me replacement shafts and bearings.
When replacing roller bearings on the Model A, try to find NOS.
*Look carefully at the left bearing end plate and you will see where the roller has worn a groove into the plate.
I removed and dis-mantled the Mitchell transmission and discovered defective roller bearings. The same type of problem that has occurred on newly manufactured rear wheel roller bearings is now occurring on transmission roller bearings. They are manufactured very poorly. These bearings have been sold by at least one major Model A parts vendor and installed in both original & Mitchell transmissions. The bearings used in both transmissions are the same part number. In some cases the end plates seem to be soft and the rollers eat through. In other cases the bearings are warped and don't spin properly. Also, there appears to be a design change in the rollers form NOS to newly manufactured. The old style bearings had an axle at each end of the bearing that fit into a hole in the end plates. The newly styled bearings have hollowed out ends on the rollers that fit into small round protrusions on the end plate. See the attached photos.
Mitchell has been excellent with their response & support. They sent me replacement shafts and bearings.
When replacing roller bearings on the Model A, try to find NOS.
*Look carefully at the left bearing end plate and you will see where the roller has worn a groove into the plate.
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Tom Endy
Well-known member
The link to this post appeared several weeks ago on fordbarn and is very disturbing. I immediately checked my stock of transmission roller bearings I obtain from Bratton's. Since I rebuild transmissions for several outlets I was very concerned. My stock turned out to be of the original design. I spoke with Walt Bratton about it and he told me they have been using the same supplier for many years.
Who ever is the manufacturer and retail supplier of these inferior bearings, it would do the Model A hobby a favor if they would be identified here on this forum.
Changing out the three roller bearings in the transmission is not a big effort, but getting the transmission out of the car is.
I know of one fellow club member who has a Mitchell syncro transmission that has a several hundred miles on it and it just screams. I suspect it has the inferior bearings in it.
Tom Endy
Re: noisy Mitchell transmission. SAME SAME in stock transmission rebuilds of late ...
I built a stock A transmission 20 plus years ago with a new set of Mark gears. It was quiet at first but screamed like crazy after 2,000 miles.
After another 2000 miles I tore it down to see why all of noise.
One roller bearing self destructed like photos above in post #26. Wiped out 2nd slider and matching gear on cluster ie the surface of gear teeth where they mesh is damaged.
Again all of these were brand new Mark gears.
Note added: Bearing that was destroyed was inside the cluster gear. So one end of Cluster gear was flopping around which caused damage to gears and noise.
I built a stock A transmission 20 plus years ago with a new set of Mark gears. It was quiet at first but screamed like crazy after 2,000 miles.
After another 2000 miles I tore it down to see why all of noise.
One roller bearing self destructed like photos above in post #26. Wiped out 2nd slider and matching gear on cluster ie the surface of gear teeth where they mesh is damaged.
Again all of these were brand new Mark gears.
Note added: Bearing that was destroyed was inside the cluster gear. So one end of Cluster gear was flopping around which caused damage to gears and noise.
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