Clunking sound on shift.

[Tinster]

I have very little actual drving time
on the Crypt car. It clunked when I bought it.

I had the right front diff mount repaired and new
mounts, gaskets, oil seals etc. installed for the diff.

I have driven the car now three times. There is still a
substantial clunk when I shift. forward or reverse, no
difference.

How do diagnose what it is the clunk so I can order the parts when I order the clutch parts?

BTW-New coil springs, all new bushings in rear end, refurbished shocks, new trailing arm bushings and mounts.

thanks

d

 

[cjm]

sorry to say i keep meaning to look through info on your car,so i could be way off the mark here, the first area i'd check is prop.is there play,rotational either way.worn splines.loose bolts.worn diff drive pinion splines.gearbox mount+plate.
crown & pinion adj',oil in diff,driveshaft joints,diff gears.anything close in engine bay.as you'll appriciate car wear usually comes out as noise. /ubbthreads/images/graemlins/cheers.gif

 

[DougF]

Other things to look at. Rear shock bolts could be loose. Possible u-joint problem.

 

[Tinster]

Installed the shock bolts myself.
But to be safe, I just checked.
Tight as can be.

The thunk is not the shocks.
So we have ruled out shocks thunking.

Thunk happens even when car is at rest
and I put it into 1st or reverse and let
out the clutch.

Thanks Doug

I rebuilt/replaced the entire rear suspension
myself over the past nine months.

I don't think the suspension is causing the clunk.
I think the clunk is drive trane related somehow.

 

[LastDeadLast]

U-joints or worn axle spines, probably in that order. Unless there's something really, really worn, and I mean really, the spines probably don't represent a relative risk, the u-joints however, do.

Since the mechanical condition of the car is relatively unknown, I would replace all six of them just to be sure. Since you'll have the tranny out it should be that big a deal.

You can also buy complete spine axles from Moss if you're interested.

 

[Tinster]

I'm not quite sure where the 6 U-joints
are to be found.

Here is some data to help diagnose my clunking
sound on shifting.

I jacked the rear end of the car so both wheels
were off the ground. Transmission in gear.

I can rotate each wheel approximately 2"
(tire edge measurement) either forward or
backward before the opposite wheel moves.
These IS a sound when the opposite wheel engages.
There is a louder clunk when I move the wheel rapidly.
It clunk appears to be between the two wheels and
NOT along the drive shaft line.

In neutral,

Both wheel spin easily until a point of resistance
is felt. It almost feels like the hand brake has been lightly pulled and then let off. I can also hear
barely a whisper of metal on metal when the
wheel spin resistance is met and then passed thru.

Curious: I now have an oil leak from somewhere near
the diff. I replaced EVERY oil seal and gasket
in the car from the transmission backward. I cannot
image a new oil leak with less than 20 miles on
everything new.

So, any more ideas on the origin of my clunk
on shifting?

thanks,

Tinster

 

[Brosky]

How about raising the car and supporting it with jack stands so you can get under it. With the car in gear, engine OFF, and e-brake on, attempt to rotate drive shaft. Is there any amount of excessive play or noise?

None, good, now release e-brake and try turning again. It will be tight, but go back and forth with the shaft and notice any play or noises.

If you have a noisy or worn u-joint, you may be able to find it in this manner.

 

[Tinster]

Thanks Paul,

I'll try that tomorrow!

d

 

[Brosky]

Dale, I can't believe that I didn't remember this. Your clunking may be a loose or cracked rear transmission mount. While you are under the car, use a pry bar or big screw driver to pry up on the rear transmission mount. It's hard rubber,so you'll have some flex, but if it separates or the bolts are loose holding it to either the frame or onto the tranny itself, you have found your noise. As these get old, they breakdown from old age and oil and develop cracks.

 

[angelfj1]

The rear axels are each made up of 2 pair of half-shafts. The half-shafts are splined similar to the drive shaft. This allows the axels to move in ond out as the suspension operates. The joint is the area under the rubber boots. I was experiencing similar sounds this past summer. When we removed the half-shafts we found that the splines were badly worn. Each time the axel rotated there was a clunk as the sides of the splines engaged. This condition can not be repaired. The solution was to replace all four half axels. We did this and while we had the car up on stands we also replaced the u-joints and properly lubed all of the joints. Be sure to use quality u-joints. There are some really bad ones out there. Ask Dave H at TRF. He is a personal friend and will take care of you. Here’s another tip. Because they are hard to reach, many owners and mechanics do not properly tighten the nuts and bolts attaching the axel and differential flanges. I found that a pair of flare nut wrenches worked good They are a bit thinner material and longer I was able to exert more torque. Be sure to use new hardware , bolts and nyloc nuts. They take quite a bit of shear loading. , so be sure they are grade 3 minimum (I use grade 5). TRF can supply these too. So, in summary I suspect motion in the three splined shafts (drive shaft and two axel shafts), are the source of the clunking sound.
Buena suerte y saludos

 

[Guest]

Actually to tighten, a 24" extension bar with a 9/16" socket works wonders. Put a wrench on the back and use this to tighten. Works wonders.

 

[LastDeadLast]

This noise could also be a worn diff... the leaks probably are anyway. My diff was probably 1000 miles from trashing the ring and pinion gears before it was rebuilt...

 

[Tinster]

Paul: I think you called the "Thunk" correctly.

Beautiful day, not a cloud in the sky so I got
the Crypt Car started and headed out to attempt
to make it to the mechanic's shop w/out breaking down.

So what does the Crypt Car to get me back? A friggin'
black cloud came from nowhere and belched water into
my top down TR.

Here's where the expert Brit car guru thinks the clunk originates. And he is pretty sure the Crypt Car has a
racing clutch installed. Maybe that explains the TR250 engine?

 

[startech47]

Check the motor mounts and transmission mount. OLd ones can get too soft and allow the movement or they can be sheared off. This is a simple fix. Phil

 

[martx-5]

We had a TR4 at our tech session last week that had a clunk, and it turned out to be a totally disentigrated trans mount. It wasn't holding the trans in place at all. We replaced it, and the clunk was gone. So, check that trans mount, especially since you indicated that the trans seems to rotate.

 

[Brosky]

I had a feeling that it was the mount. If you have access to a lift, get both engine mounts and the trans mount, which should be a single unit on your early style. If the tranny mount is gone, the motor mounts are probably right behind it. Do them all while in the air, it will only take another 1/2 while up and with a jack to help lift an inch or so.