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MG TD TF 1500 - Listen to my noisy TF gearbox (HELP)

Will you give me your opinion of the source of noises in my TF-1500 gearbox and possible fixes before I remove it again? See and listen to videos linked below.

I didn't know how bad the gearbox sounds until I recorded the videos. In the interior videos, the microphone was pinned to the carpet at the base of the shifter.

HISTORY:
I knew nothing about gearboxes except for the Workshop Manual and a borrowed copy of Barrie Jones' video when I did some repairs on my gearbox. I was so confident in my newfound skills that I installed new floorboards and carpet before ever testing my work. (dumb)

I replaced the rear case of the gearbox because the eye for the rear mount was broken. Other than clean out the sludge in the gearbox, I did not touch the gears. I did not change any shims. I replaced the U-joints, clutch, pressure plate (torqued to 19 ft-lb), release bearing, gearbox rear bearing, gearbox rear felt oil seal, gearbox front oil seal, square bolts on the selector shafts under the remote control and lockwired them. I removed the gearbox cover, but did not lose the three balls or springs. I left the gears in neutral throughout the process.

Now my entire drive train rattles severely when I slowly release the clutch in reverse. It shudders somewhat when I release the clutch in 1st gear. And it shudders when I let out the clutch in a downshift if the engine RPM is lower that the gearbox RPM. The clutch is not slipping. Everything is fairly quiet with no load at speed in 4th.

Although I haven't put a wrench on them, the U-bolts on the rear springs appear to be tight.

I have been advised to replace my clutch linkage rod with Moss 190-122 adjustable clutch link rod because mine is bent. I doubt that this is causing my problems.

VIDEOS: <><><> Links don't work. Must copy and paste.
> This is how the car feels and sounds when I back it into the garage applying and slowly releasing the clutch a few times.
https://www.youtube.com/watch?v=ZCUTMfcFjKg


> This is how the engine and running gear shake in reverse while slowly letting out the clutch. You may not be able to tell, but everything shakes. Look how the engine also shakes. It's worse if the clutch is slowly released while the hand brake is set.

(1440X1080 pixels)
https://www.youtube.com/watch?v=MlgvJ1lIEvk

(640X480 pixels - same video as above, lower resolution)
https://www.youtube.com/watch?v=_8xi-zVykZs


> Accelerating in reverse, first, and second then coasting in gear downhill.
https://www.youtube.com/watch?v=AcWFs6F1Aqc


> Moderately hard acceleration. OUCH - bad downshift into second.
https://www.youtube.com/watch?v=gG31cnL7VnU


> And finally ... "Chassis Cam"

(1440X1080 pixels)
https://www.youtube.com/watch?v=Q5kqtOzBhvA

(640X480 pixels - same video as above, lower resolution)
https://www.youtube.com/watch?v=yb9birzehFg

++++++++++

My uneducated newbee-guesses:

"CLACK"
The pressure plate is not applying pressure evenly. I understand that new pressure plates can sometimes be defective. Worn splines in the rear brake drums "clack" when the clutch shudders.

"GRIND"
I thought that the grinding noise could be corrected by adjusting the anti-rattle plug in the remote control cover. But after hearing the videos, it sounds like I have troubles in the bowels of the gearbox.

I'm totally lost. Thanks for any advice that you can give to me.

Lonnie
TF7211
LM Cook

Lonnie, fyi if you remove the "s" in the "https" in your links before you save the post the links will be clickable. (Don't ask me why!)
I did the first one:

http://www.youtube.com/watch?v=ZCUTMfcFjKg

Ed
efh Haskell

Sludge is never a good thing, especialy if its metal.

so is it only juddering in 1st 2nd 3rd and reverse?

if so I would say layshaft, I am sure it is supported by the backplate and should be shimmed, changing a backplate that might be worn would cause problems, if not highlight worn layshaft bearings.


could be wrong, but its my guess.
good luck
mog

ED - THANKS. I REMOVED THE "S" AND REPOSTED MY QUESTION BELOW WITH WORKING LINKS.

=======

Will you give me your opinion of the source of noises in my TF-1500 gearbox and possible fixes before I remove it again? See and listen to videos linked below.

I didn't know how bad the gearbox sounds until I recorded the videos. In the interior videos, the microphone was pinned to the carpet at the base of the shifter.

HISTORY:
I knew nothing about gearboxes except for the Workshop Manual and a borrowed copy of Barrie Jones' video when I did some repairs on my gearbox. I was so confident in my newfound skills that I installed new floorboards and carpet before ever testing my work. (dumb)

I replaced the rear case of the gearbox because the eye for the rear mount was broken. Other than clean out the sludge in the gearbox, I did not touch the gears. I did not change any shims. I replaced the U-joints, clutch, pressure plate (torqued to 19 ft-lb), release bearing, gearbox rear bearing, gearbox rear felt oil seal, gearbox front oil seal, square bolts on the selector shafts under the remote control and lockwired them. I removed the gearbox cover, but did not lose the three balls or springs. I left the gears in neutral throughout the process.

Now my entire drive train rattles severely when I slowly release the clutch in reverse. It shudders somewhat when I release the clutch in 1st gear. And it shudders when I let out the clutch in a downshift if the engine RPM is lower that the gearbox RPM. The clutch is not slipping. Everything is fairly quiet with no load at speed in 4th.

Although I haven't put a wrench on them, the U-bolts on the rear springs appear to be tight.

I have been advised to replace my clutch linkage rod with Moss 190-122 adjustable clutch link rod because mine is bent. I doubt that this is causing my problems.

VIDEOS:
> This is how the car feels and sounds when I back it into the garage applying and slowly releasing the clutch a few times.
http://www.youtube.com/watch?v=ZCUTMfcFjKg


> This is how the engine and running gear shake in reverse while slowly letting out the clutch. You may not be able to tell, but everything shakes. Look how the engine also shakes. It's worse if the clutch is slowly released while the hand brake is set.

(1440X1080 pixels)
http://www.youtube.com/watch?v=MlgvJ1lIEvk

(640X480 pixels - same video as above, lower resolution)
http://www.youtube.com/watch?v=_8xi-zVykZs


> Accelerating in reverse, first, and second then coasting in gear downhill.
http://www.youtube.com/watch?v=AcWFs6F1Aqc


> Moderately hard acceleration. OUCH - bad downshift into second.
http://www.youtube.com/watch?v=gG31cnL7VnU


> And finally ... "Chassis Cam"

(1440X1080 pixels)
http://www.youtube.com/watch?v=Q5kqtOzBhvA

(640X480 pixels - same video as above, lower resolution)
http://www.youtube.com/watch?v=yb9birzehFg

++++++++++

My uneducated newbee-guesses:

"CLACK"
The pressure plate is not applying pressure evenly. I understand that new pressure plates can sometimes be defective. Worn splines in the rear brake drums "clack" when the clutch shudders.

"GRIND"
I thought that the grinding noise could be corrected by adjusting the anti-rattle plug in the remote control cover. But after hearing the videos, it sounds like I have troubles in the bowels of the gearbox.

I'm totally lost. Thanks for any advice that you can give to me.

Lonnie
TF7211
LM Cook

mog -

The "sludge" was a gray slurry. Gear oil and powdered metal, I guess. It covered everything equally. The dreaded word "layshaft" was mentioned when I showed my problem at GOF-South.

Things may have gotten loose when I changed the rear case. I didn't shim anything.

The shuddering is most evident at low engine RPM and slow release of the clutch. Reverse is worse. 1st is not as bad. 2nd even less. Not sure about 3rd and 4th. Shudder also sometimes in 4th-to-3rd downshift and 3rd-to-2nd downshift.

Will I damage the gearbox by driving it a few miles before I fix it?

Thanks,

Lonnie
TF7211
LM Cook

Tis a pain I know, but if it was my call I would quicky remove the box, lift the lid and have a look, its not difficult or expensive to change the bearings.
mog

What happens if the fearbox is in neutral and the clutch is activated? Is everything smooth if the car is coasting in, say, 3rd gear with the clutch depressed? Was the clutch driven plate installed the right way around? How did you install the felt seal at the rear of the extension? This definitely does not sound like bearing noise.
Hugh
H.D. Pite

I know the problem! It's way too clean under that chassis!
efh Haskell

Lonnie,

You mentioned that you changed the U joints, they may be the problem. You should drop the drive shaft from the gearbox and from underneath listen to the box while a helper changes the gears. If it is not the U joints, you can at least get some useful information just by listening while you are under the car.

John


J Scragg

Ideas:

1. U-joints not in the proper orientation to each other

2. axle shackles worked loose as rubber get compressed

3. The rear transmission mount is not secured properly for some reason in spite of having been replaced
Don Harmer

Lonnie is your universal joint hitting the steel gearbox cover ? Just a thought .

Gerard
Gerard Hengeveld

How about a broken clutch pressure plate spring, or two? Uneven pressure as it slides on the clutch plate will sound exactly like that shutter.

The grinding.... I've heard before in my MGB (in 1974) just as the cluster gear shaft was going egg shaped. The cluster cocked just enough to knock off a few teeth.

I'd pull it all apart before something bad happens.

....
MAndrus

Check out your front engine mount and also the stabilizer assembly on the front of the engine. These are just as important as the tranny rubber mount when it come to shuddering.

Mark
Mark Strang

Thanks to all of you for your help and suggestions. I'll check out each of them.

I'll put the car on jack stands next week and do some tests, then start pulling the carpet, floorboards, and gearbox for a complete tear-down.

I hope that a local shop will let me assist in the tear-down and rebuild so that I can learn. I would do it alone, but I don't have experience to be able to recognize the little things that could be a problem. I don't want to pull out everything again!

For what it's worth - attaching the microphone to the carpet on the gearbox cover really opened my eyes to my problem. It picked up sounds that I couldn't hear clearly with wind blowing past my ears. I recorded the interior videos with my iPhone and its hands-free mic.

I'll let you know what I find.

Lonnie
TF7211
LM Cook

Lonnie

Here is a link that should give you an insight on rebuilding an XPAG Gearbox

http://www.mgccyregister.co.uk/

After you enter the site select Technical Information from the list. When the page opens go to the bottom and select "Gearbox Rebuild".

The guy who collated this was so thorough I reckon my missus could follow his instructions, that is really saying something.

Graeme
G Evans

On the acceleration vid, it seems like the "sputtering" is more like happening at the same speed as the engine,,, almost like a leaking exhaust manifold gasket,,,,,
It is definitely not sounding like a loose axle "U" bolt,,
Steve Wincze

Just listened to it again,,, One of the noises sure sounds like an exhaust manifold gasket,,,



SPW
Steve Wincze

Steve -

You may be right. The nuts on all of the manifold studs were loose a few months ago and I tightened them. Hadn't retightened since I installed the head last year. I looked and listened for exhaust leaks and couldn't find any. I may have missed them. I'll check again.

Lonnie
TF7211
LM Cook

Graeme -

Thanks for the link to the gearbox manual. Well written and the photos are really good for a newbee like me.

With the manual, the Workshop Manual, and Barrie Jones' video, I should be able to rebuild the gearbox. However, I will probably get some professional help. Hopefully, I can find someone who will let me work along side so that I can learn.

Hope to do some tests while on jack stands later this week. Then remove the gearbox next week.

Thanks to everyone for your help and diagnoses.

Lonnie
TF7211
LM Cook

I'm gonna pull the gearbox out of my TF again. This time I'll do a complete tear down plus remove the flywheel and have it resurfaced. I'll learn as I go.

I drained the gear oil. No metal shavings, teeth, or surprises.

Club members are coming to my house this Saturday to help me remove the gearbox. Everything is out of the cockpit, so it should take just a few minutes. Only need one person, but the others will give moral support and drink beer.

We will probably have a club Tech Session when I tear it apart and reassemble it. I may disassemble and reassemble before they come so I don't look like a complete dufus when I do it in front of the group.

Thanks again for your help and suggestions.

Lonnie
TF7211
http://www.classicmgclub.com/
LM Cook

Lonnie.
From the noise that I heard I would stronly suspect laygear/Shaft and bearing at least.That could be the source of the grey sludge
PS I should have a good used laygear if needed..
Sandy
SANDY

We removed the gearbox from my TF yesterday, removed the cover, and looked inside. I have good news and bad news ...

GOOD NEWS
Everything looks OK inside.

BAD NEWS
Everything looks OK inside.

So I'll proceed to tear it apart.

The flywheel looks good. I may do more harm than good by removing it. I'll check it for runout. If OK, then I will scuff it and nothing more. From the A.32 in the WSM:
"Check the flywheel for accuracy. It should be no more than .002 in. (.05mm) out of truth at any point when rotated with a dial gauge in contact with the clutch face."

>> What can I do to check the pressure plate for problems? (less than 300 miles)

>> Sandy - Thanks. I may need to take you up on your offer of a laygear. You have known my car longer than I have!

Lonnie
TF7211
LM Cook

I disassembled my gearbox.

I couldn't remove the layshaft from the gearbox because the locating screw in the bottom of the case that secures the layshaft was broken off at the tip. A club member showed my how to drill it out today. With the screw no longer locking the layshaft in place, I inserted a dummy and finished the teardown.
See thread title: "Remove broken layshaft locating screw(?)"]

You guys were right about the layshaft. It looks pretty bad under first/reverse. Everything else looks good.

Just speculating ... wonder if the bad layshaft vibrated enough to stress-harden and crack the locator screw.

>> QUESTION ABOUT NEW LAYSHAFT:
I have heard that some replacement layshafts a few years ago were not hardened correctly and failed. A club member can sell me an unused layshaft that was purchased about 10+ years ago. Should I buy it or buy a new one from Moss?

I'm hoping that new bearings, needle rollers, layshaft, and pilot bushing will correct the grinding noise in my gearbox. I will clean and inspect everything plus check for clearances and add shims if necessary.

The shuddering problem is still a mystery. Possibly just some grease on the clutch, but it never burned off in use. I don't know how to check the new clutch and pressure plate for defects.

I'll post more info as I rebuild, install, and test the gearbox.

Lonnie
TF7211

Image: Spalted layshaft at rear.

LM Cook

That is pretty much where the shaft went egg shaped in my MGB in '74. Good thing you caught it. I didn't and it cost me a few new gears.

...
MAndrus

As Yogi Berra said, "It's deja vu all over again."

I finished tearing apart the gearbox for my TF. First gear on the laygear is damaged. In searching the archives, I found a thread started by Alex Waugh. I don't need to post photos of my gears. Photos of his laygear look exactly like mine. Alex's retaining bolt for the layshaft was damaged. Mine was broken.

Search the archives for 201401240546023550

I'll show my parts to members of our MG club meeting this Thursday night to get their opinions and suggestions. Deep down, I know that I will need to bite the bullet and buy a laygear and a layshaft. Plus some smaller parts.

Barney Gaylord, "MGA Guru," says that layshafts from Moss were not sufficiently hardened in the past. Has the problem been corrected?
http://mgaguru.com/mgtech/gearbox/gt204a.htm

>> Any information about the quality of new layshafts and new laygears? What are the best suppliers?

Lonnie
TF7211
LM Cook

Hi Lonnie, That article only mentions MGA shafts. Different and different part # for TD/TF. I didn't think the score on your layshaft was bad enough to cause that much noise. George
George Butz

I checked the Moss UK site. No information about a harder layshaft for T-series cars. The hard and the not-so-hard layshafts for MGAs are on the UK site. I haven't spoken to Moss USA by phone.

George - I've exhausted my level of ability and experience to determine the condition of my gearbox. I'll show the major parts to some experienced members of the Classic MG Club. I'm still hoping to hire a local MG repair shop owner to look over my shoulder while I assemble the box. I really want to do it myself.

First gear looks pretty rough. Everything else inside looks good to my untrained eye.

My next parts order to Moss is up to about $1,500 and growing. Maybe if I throw enough new parts and cash at my problem, it will go away.

Lonnie
TF7211
LM Cook

Maybe supply Will with some beverage and have him supervise? The new batch of Moss repro gears are supposed to be really great, no experience with them. How about posting some pictures of the gears and cluster? You really want to do it right the first time. With bending lock tabs over, removing the first motion shaft nut, etc., there is risk of damage from disassembly, so better to do it once if possible. You could always take it to Glenn in St. Pete? George
George Butz

This thread was discussed between 26/04/2015 and 19/05/2015

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