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MG TD TF 1500 - 'CLUNK' from rear of my TF

I'm greeted by a loud "CLUNK" from the rear of my TF when I accelerate from a stop.

> What's my problem? How to fix? Suggestions?

I installed new axles and nuts from Tom Lange in May 2024, so I'm sure they are still good.

This video shows the rear components.
https://www.youtube.com/watch?v=ooak8V3UuPI

Thanks for your help,
(I am posting this on both forums)

Lonnie
TF681
TF721
LM Cook

Hi Lonnie. Check your axle nuts! bring them up tight then keep turning until the next cotter key hole. I usually put the trans in gear parking brake set, car on ground. Put a breaker bar on the nut wit a 2 ft pipe extension then stand on it until you get to the next cotter key hole.

Butch
R Taras

Thanks Butch -

I followed Tom Lange's installation instructions. I tightened the axle nuts to at least 150 ft-lb. (not easy!)

Lonnie
TF681
TF7211
LM Cook

You have wire wheels correct? Make sure the knockoffs are good and tight. I usually give them another pounding after wheels are off and I have driven for a day or so.
Christopher Couper

The play in the differential is more than it should be, so that could be causing a clunk. What concerns me most is what appears to be in/out play of the pinion as you turned the drive shaft. That would suggest a problem with the gear lash or possibly a bad bearing.

Moving beyond that, you have a massive amount of play between both of the wire wheels and their hubs. Honestly I wouldn't even drive the car like that for fear it might allow the spinner(s) to come loose or spin a wheel.

A few things could cause this, most commonly a wheel that has been over-tightened. When you over-tighten the spinner, it forces the rear taper of the wheel up the hub taper, stretching the wheel hub out. As this happens, then wheel goes farther and farther onto the hub until it contacts the brake drum nuts at which point you lose the needed friction between wheel and hub. If this is the case, there is no choice but to replace the wheel, or rebuild it with a new center. I would remove the wheel, put a dab of grease on each brake drum nut, and reinstall the wheel. Then remove it again and see if there are grease marks on the back of the wheel. That will tell you if there is an interference issue.

Also make sure you grease the outer part of the wheel center, where the spinner covers it up. If left dry, there can be a lot of friction between the spinner and the wheel's painted surface which can prevent the spinner from fully tightening. This is especially an issue on chrome wheels.

There will always be some play in the splines when the spinner is loose, but once tight there should be zero play, especially by hand.

Good luck!
Steve Simmons

Thanks, Steve and Chris -

I noticed the in-out movement of the driveshaft at the diff, too, and assumed it wasn't a good thing. Glad that it showed on the video. I was hoping that a couple of thousand dollars spent on hubs and wheels would fix my clunk. The diff has me concerned. I would not attempt to repair - - a job for an experienced MG diff guy, if parts are available.

The wheels turn on the hub splines when the spinners are fully tightened. I first saw the movement when I was trying to find the source of the clunk. I rocked the car back and forth with the brake on and the spinners tight, and saw the wheels turn on the hub. Just to be sure, I pounded the spinners again and the CLUNK continued. I didn't rock the car with the brake on to confirm that the wheel still moved on the hub.

I haven't driven the car since I saw the play in the wheels/hubs. Too many friends have told me about wheels coming off when splines were worn.

Since I have owned the car, about 4 years, I have kept the splines and spinners greased. The tapered joint between the hub and the wheel has a wipe-on / wipe-off layer of grease or anti-seize to protect against corrosion, but not greased.

As I investigate more based on comments on the forums, I'll check again with the spinners fully tight.

Lonnie
TF681
TF7211
LM Cook

Even with fully stripped splines, I doubt you could turn the wheel like that if the spinner was tight. There's something definitely wrong! Did I read it right that you already installed new hubs and wheels? If so then I have no explanation why you're having this issue, especially on both wheels, unless something is seriously out of spec. That much movement with 50 HP of torque will definitely wear the splines quickly.

If you need diff parts, I have a couple complete, original TD/TF diffs that look really good. I'll give you a great deal if you need them. I don't have a TD anymore so they aren't doing any good sitting here.
Steve Simmons

Is there a tiny chance you have the hubs on the wrong side of the car?

The knock offs are labeled backwards since the cars are made in the UK.
Christopher Couper

Lonnie.
I had something similar some time back and found the 6 studs that hold the knock off hub to the drum were disformed. The small studs have splines and they were crushed to make the stud round. Allowing movement between the hub and the drum. I purchased new hubs and studs but to be honest the new studs from Moss are very soft? and one even stretched when just tightening it. Not sure what the proper torque is but I just had them pressed into the hub and snugged them up tight and then formed the lock washers up to them. Fixed the clunk noted on hard acceleration and then sharp breaking. Still have a bunch of slack in the diff though and mine I got form Dave Clark with new half shafts. I think it is normal.
Rod





Rod Jones

Your backlash looks about right but the diff drive flange should not be moving in and out. First thing I would do is remove the prop shaft and check the pinion nut is tight. If it is not, that's one problem solved, but if it is you have a problem with the pinion bearings.

On your main problem, as everybody agrees, the when should not be moving on the hub. You stated you just changed them! do you still have the old hubs and wheels? If so do a mix and match, try old wheel on new hubs, old hubs in new wheels to try and identify which component is wrong. To get that much movement the OG of the hub could be 1mm to small or the ID of the wheel 1mm to big. If you don't have them maybe somebody with a car nearby can come and check their wheel on your hubs and your wheel on theirs.

Good luck
B W Wood

Hey guys,

Thanks for your knowledge and suggestions.

Here’s my plan:

1) Buy new hubs and 48-spoke painted wheels. I probably wasn’t clear … I did not purchase and install new wheels and hubs previously. The hubs are in the correct location.
>> Can any of you recommend a good wire wheel maker / seller of tubeless wire wheels shipped to me in Orlando, FL?

2) Opinions about the diff vary pretty widely. I’ll check the nut on the pinion for proper tightness. Don’t know if I can torque it to spec if it is loose. The lash and movement is much more than the lash on my other TF that’s a stalled restoration.

3) I’ll remove the diff and take it to a club member who is our differential guru for inspection and rebuilding.

4) Do some I’ll do some “While-I’m-at-it” jobs like new spring bushes, U-joints, new pads in the leaf springs, new U-Bolts, and more.

>> Any suggestions for me and some club members to remove the remove the diff while the car is on jack stands?

Thanks again,

Lonnie
TF681
TF7211
LM Cook

Wheels: MWS or Dayton. Both are good. MWS are probably going to look more original.

Diff: I believe on your car the axle splits in two to get at the diff, so jack stands on the frame rails.
Steve Simmons

Lonnie - you've received good advice, and you're on the way to correcting everything. May I add: what a great (brief) video to clarify your issues. Way above my skillset, but could you advise what the camera setup is? Thank you. John.
J P Hall

Lonnie--just watched your video.
Starting from the front, the gearbox movement looks about normal
The universal joints appear ok
The diff movement is no good, I suspect this is where the bulk of your noise is coming from--- removing the tailshaft and checking the pinion nut would be the first step, if that is loose and tightening it up rectifies the in/out movement you 'might' get away with just tightening the nut if there aren't any other diff noises.
Wheel movement like that is bordering on dangerous, problem being if you hit the brakes and the wheel rotates on the splines it undoes the knockon and the wheel comes off---Just looking at the splines in the vid. the lh one is worn and the rh one is really worn.
I note that you're going to get new hubs and wheels but just for checking with your vernier calipers-

A new splined hub measures 2.450 inches (42mm) in diameter across the outside of the splines and the splines have flat tops. 2.430 inches is the absolute throw away limit--
willy
William Revit

A RED-FACED UPDATE

Even though many of you suggested that I should tighten the knock-offs on the rear wheels, I was convinced that the wheels moved on the hubs no matter how hard the knock-offs were tightened.

Well, today I mounted the rear wheels and pounded on the knock-offs to get them tight. I marked a spot on the inside edge of each rear wheel and a corresponding spot on the brake drum with a paint pin. I went for a drive and made some hard stops both forward and reverse. Looked at the spots on both wheels after two runs. You guessed it. The spots were exactly where I had made them on the wheels and drums. The only clack was from the diff.

Anyone know where I can get good reasonably priced 4.11 gears for the diff while it's being rebuilt?

Thanks for your help that I didn't listen to!

Lonnie
TF681
TF7211
LM Cook

That's great Lonnie. Are you sure you want to go as low as 4.11? I thought 4.321 was too low back in the day. But folks who don't climb mountains much think 4.3 is the best.
Christopher Couper

Hey Chris ...

A RED-FACED UPDATE (2)
I meant to type 4.55 gears. Guess I was thinking about 60s Chevys 4.11 drag gears!

Even though Florida is flat as a pancake, I feel that 4.55 is better for Jo Ann's tired 1250 TF. Should make the engine feel better at 60mph than the current gears (which may be 5.125 instead of 4.875(?) Plus, I'm not an interstate speed demon.

A friend had 4.30 gears in his TF-1500 at "Mayhem in the Mountains" MG gathering in Georgia a few years ago. He stopped on a mountain road and couldn't go up hill when he tried to start in 1st gear. While we were coasting back down, I decided that 4.55 was good for me.

Lonnie
TF681
TF7211
LM Cook

Lonnie: That is good. You scared me. I think 4.33 is to high too. 4.55 would be good if you can find it but 4.875 is fine too.

My car still runs the 5.12 but I never get on a freeway and if I do, I get to listen to horns the whole time I am doing 55 mph in the far right lane.
Christopher Couper

So the knockoffs were just loose? That's a much cheaper fix than new wheels and hubs! I would inspect the splines just to be safe though, especially if they had been driven on like that.
Steve Simmons

Lonnie,

I have a 4.55 in my TD and a 4.3 in my TF1250, I can cruise all day at 70mph but neither of my engines are standard and my body tubs are panel are in Aluminium. I cannot remember the exact numbers but you have to go a bit more than one step just to make up for the change in diameter from cross ply to radial. So one step will get you back close to original gearing if you run modern radials.I will have a look at what I have got in used, I do have a NOS 4.875 still in its box.

Bernie
TD
TF1250
MGA 1500
TF 120 Stepspeed
67 E-type FHC
B W Wood

Walking in and out of the pinion is caused by bad pinion bearings. Which will cause excessive lash and cause a premature CW&P failure. Generally with a bearing failure the union seal will fail.

Bill Chasser
TD-4834
TD/c-8151.
W A Chasser

This thread was discussed between 08/07/2026 and 15/07/2026

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