Excessive noise on bench test after transmission rebuild

Started by 2017FLHTK, November 19, 2021, 08:23:51 AM

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2017FLHTK

I'm in the middle of my first transmission rebuild (on a 1979 FL). All internal parts are new Andrews, including the bushings / gears / dogs / mainshaft & countershaft. Obviously new bearings inside the gears, and the mainshaft bearing on the kicker end is brand new as well. The (new) Koyo transmission drive bearing on the case was installed to the proper depth with the correct Jim's Tool.

Here's a list of the parts used:

Gears:
-1st Gear, 2.44 Ratio, Part Number 201105 [correctly paired for 2.44:1 first gear / 1.35:1 third gear set]
-2nd Gear, Stock 1.82 Ratio, Part Number 292160
-3rd Gear, 1.35:1, Part Number 203375 [correctly paired for 2.44:1 first gear / 1.35:1 third gear set]
-4th Gear, stock 26 tooth main drive gear (1977-1986), Part Number 204280

Shift Clutches
1-2 Shift Clutch, Part Number 205120
3-4 Shift Clutch, Part Number 205340

Shafts
-Countershaft (Late 1976-1979), Part Number 207770
-Mainshaft (2970-2986 chain drive), Part Number 208700

With just the mainshaft installed in the case, this is what it sounds like as I rotate the gears:


I have a generous coat of assembly lube applied to the shafts, bearings, and bushings. I have light coat of oil on the teeth of the gears as well. When I rotate the assembly I can hear an alarming amount of mechanical noise.


Is this the normal sound of gear engagement for a bench test? Does it just sound so loud because it's not in the oil bath it will live in once everything is buttoned up and topped off with gear oil? Or is something off?

kd

Welcome to the world of straight cut spur gears.  It sounds normal to me.  Fill it the the correct level with fear lube and retry it.  The lube will act as a cushion between the gear teeth and silence it somewhat.  Put the lid on and it will improve it even more. I think you will see a big difference.

BTW, you'll love the Andrews 1st and 3rd gear ratios if you haven't tried them yet.
KD

JW113

 :agree:

Sounds normal to me too.

What overall final drive ratio are you planning to use? I'm running 3.42 overall final drive, and even with my stock 3.0:1 1st gear, I need to slip the clutch a little. Just wondering how that 2.44:1 is going to launch. But once rolling, I'm sure that closer gear ratio set is gonna be nice!

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

bump

Sounds about right to me. As long as the gears turn without much effort and shift dogs move smoothly. Button it up and try running it through gears while turning shaft by hand.

kd

Quote from: JW113 on November 20, 2021, 10:43:25 AM:agree:

Sounds normal to me too.

What overall final drive ratio are you planning to use? I'm running 3.42 overall final drive, and even with my stock 3.0:1 1st gear, I need to slip the clutch a little. Just wondering how that 2.44:1 is going to launch. But once rolling, I'm sure that closer gear ratio set is gonna be nice!

-JW

I ran 21 and 22 trans X 51 or 49 final drive and it worked great.  I switched around occasionally but never found it too high with the lower tooth count transmission sprocket.  It did time on the highway quite a bit and had an 80 mph sweet spot.  As JW says, the Andrews first is not the stump pulling ratio you took out so you may want to consider a transmission sprocket change. The 3rd gear splits the difference between 2nd and 4th about prefect.  The OEM 3rd was very close to 4th and not all that great for sport riding.
KD

2017FLHTK

Quote from: kd on November 19, 2021, 12:03:11 PMWelcome to the world of straight cut spur gears.  It sounds normal to me.  Fill it the the correct level with fear lube and retry it.  The lube will act as a cushion between the gear teeth and silence it somewhat.  Put the lid on and it will improve it even more. I think you will see a big difference.

Great feedback. Thanks!

Quote from: kd on November 19, 2021, 12:03:11 PMBTW, you'll love the Andrews 1st and 3rd gear ratios if you haven't tried them yet.

If I ever get this project finished.....  :dgust:



Quote from: JW113 on November 20, 2021, 10:43:25 AM:agree:

Sounds normal to me too.

What overall final drive ratio are you planning to use? I'm running 3.42 overall final drive, and even with my stock 3.0:1 1st gear, I need to slip the clutch a little. Just wondering how that 2.44:1 is going to launch. But once rolling, I'm sure that closer gear ratio set is gonna be nice!

I have a 24 tooth engine sprocket paired to a 37 tooth clutch basket.  Transmission sprocket will be a 23 tooth and the rear wheel sprocket will be a 48 tooth.

According to http://www.nightrider.com/biketech/calc_gearratios.htm that works out to be a 3.217 final drive ratio.  She'll be a slug off the line, but that's ok.  I like to run around 75 mph or so on the highway, so I'll sacrifice my low-end oomph in exchange for smooth highway RPMs.



Quote from: bump on November 20, 2021, 10:51:41 AMSounds about right to me. As long as the gears turn without much effort and shift dogs move smoothly. Button it up and try running it through gears while turning shaft by hand.
Sounds good.  Thank you Sir.



Quote from: kd on November 20, 2021, 01:31:04 PMI ran 21 and 22 trans X 51 or 49 final drive and it worked great.  I switched around occasionally but never found it too high with the lower tooth count transmission sprocket.  It did time on the highway quite a bit and had an 80 mph sweet spot.  As JW says, the Andrews first is not the stump pulling ratio you took out so you may want to consider a transmission sprocket change. The 3rd gear splits the difference between 2nd and 4th about prefect.  The OEM 3rd was very close to 4th and not all that great for sport riding.

Just trying to get everything buttoned up / ok to use, but I'll keep your comments in mind if I decide that I need to fine tune the gearing on the sprockets in the future.

2017FLHTK

Taking a look at the end play today.  The mainshaft is fully assembled and installed in the case. Since I have a 1979 model I have a roller cage bearing and cannot adjust endplay on the mainshaft. I can insert a 0.014 feeler gauge between the face of the main drive gear and the transmission case wall.

I can move (ever so slightly) first gear on the countershaft gear cluster. It's possible to just barely slip a 0.004" feeler gauge in between the case bushing and the countershaft gear end washer. Technically that's within spec, but I'd ideally like something closer to the middle of the tolerance range when I set my endplay up.

I found a set of NOS / OEM thrust washers (Harley part number 35875-36) that includes all seven of the various thicknesses of washers that Harley uses to set spacing. One of those should get my end countershaft end play correctly set.

JW113

Yes, that sounds like a pretty tall first gear. Will be interesting to hear how that works out, so keep us posted.

cheers,
JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Ohio HD

Yeah I always put the 2.60:1 Andrews set in when rebuilding them. Gets the heavy scoot moving quicker.
For your bike part needs, call Calif Phil   www.harleypartscheap.com

76shuvlinoff

QuoteI have a 24 tooth engine sprocket paired to a 37 tooth clutch basket.  Transmission sprocket will be a 23 tooth and the rear wheel sprocket will be a 48 tooth.
lh
 This combo is what I have on my FLH behind a 93" mill and 5 inna 4 transmission (that I really wish had an OD)  I have played with rear sprockets from 51T down to 46T and settled on 48.  It's just my country bomber/bar hopper not an 80 mph long distance highway bike but it's still fairly happy at 70.
Being defenseless does not make you more safe.

2017FLHTK

I sent the videos to Andrews tech support and asked them what they thought. This was their response:

QuoteDoesn't sound bad although watching a video is not ideal at all/ can't hear much there. You may have a local shop experienced in transmission re-builds that may be able to take a second look/ listen? I would put the transmission in gear spin the shaft with some load on the drive gear applied by hand or hold the drive gear/ spin the shaft if in neutral (this not how QC is performed here, just giving you some ideas). Make sure the gears roll smoothly together as pairs (1st, 2nd 3rd, 4th rolled individually and make sure they don't feel "notchy") otherwise short of sending them back to be QC'd that's as much as I can recommend doing at this time

2017FLHTK

Quote from: JW113 on November 22, 2021, 03:44:40 PMYes, that sounds like a pretty tall first gear. Will be interesting to hear how that works out, so keep us posted.

Guess we'll find out when it's all done.  This is my first time messing around with gearing, so I'm mostly going on reports from other guys who seem to have a similar riding style (happy doing a steady 75mph on the freeway but don't care about taking off quick from a light).


Quote from: 76shuvlinoff on November 22, 2021, 04:35:41 PM
QuoteI have a 24 tooth engine sprocket paired to a 37 tooth clutch basket.  Transmission sprocket will be a 23 tooth and the rear wheel sprocket will be a 48 tooth.
lh
 This combo is what I have on my FLH behind a 93" mill and 5 inna 4 transmission (that I really wish had an OD)  I have played with rear sprockets from 51T down to 46T and settled on 48.  It's just my country bomber/bar hopper not an 80 mph long distance highway bike but it's still fairly happy at 70.

Everything in life is a compromise.  I just hope I picked the right all-around gearing for the way I ride.
 

JW113

Since Mark's bike is a 5 speed, it's first gear is probably around 3.25:1 or so. With your four speed and that gearing, your first gear is going to be very close to a HD 5 speed's 2nd gear. So if you have a chance to ride a EVO or TC and launch it from a dead stop in 2nd gear, that's what you're going to be looking at with this close ratio 4 speed set up.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

76shuvlinoff

November 24, 2021, 03:33:57 PM #13 Last Edit: November 24, 2021, 03:41:28 PM by 76shuvlinoff
Quote from: JW113 on November 24, 2021, 11:46:36 AMSince Mark's bike is a 5 speed, it's first gear is probably around 3.25:1 or so. With your four speed and that gearing, your first gear is going to be very close to a HD 5 speed's 2nd gear. So if you have a chance to ride a EVO or TC and launch it from a dead stop in 2nd gear, that's what you're going to be looking at with this close ratio 4 speed set up.

-JW
I tried to find the data on my 5/4. All I can find in the paperwork is it's a 2.94:1 1st and of course 1:1 5th. I know I have all the gear ratios written down somewhere, or at least I once did.  :banghead:

edit to add :
1st 2.94 to 1

2nd 2.21 to 1

3rd 1.57 to 1

4th 1.23 to 1

5th 1 to 1
Being defenseless does not make you more safe.