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MG TD TF 1500 - Front Crank Seal

I am putting together the bits for a front crank oil seal replacement in the next month. I bought a 120-750 seal from a local supplier and a new sump pan gasket and timing cover gasket. I have read all the threads on this topic I believe, but want to try this approach first.

In anticipation of some potential shaft scuffing, fitting a Speedi Sleeve. P/N 99138 is suggested but this has a variety of alternative dimensions. For the XPEG crank, which (in the link below) is the most suitable for locating the oil seal (diameter and width)?

https://www.aimsindustrial.com.au/skf-99138-speedi-sleeve-34.823-34.976mm-shaft-rang

Last, I have a good range of sealants (Right Stuff, Ultra Copper, etc) but not sure which one is best to locate the lip seal with a little flexibility?

Many thanks Merv.
M Hyde

Hi Merv
99138 is the sleeve you need
There are no alternative sizes
The SKF site might offer different choices but you'll find the part number will be different and they won't be suitable
99138 is the known sleeve for this job
Not everyone fits the sleeve as the seal sits past the end of the scroll--but yeah ,do it

As far as sealants go, I'm a big fan of Permatex Ultra Grey ,it's a really good all round sealant and coolant proof as well, it sets up probably a bit firmer than Ultra Black but still a bit flexy and the added benefit of being multi use being coolant proof, best stuff ever for gearboxes etc for metal/metal joints---that's what I'd be using/recommending ---it's good stuff

willy
William Revit

Good man. Thanks Willy. That really helps.

Merv
M Hyde

if you have access to a lathe, make up a dummy seal in metal.
Blue this and use it to witness mark the sump and timing cover and remove excess material. The rope seal groove is seldom concentric with the crank and can offset the new seal
Ray TF 2884
Ray Lee

Thanks Ray and Willi. I will be staring this task next week and have assembled all the potential parts, I believe.

The front crank seal is the main target. However, the present leak (3-4 drops after a short run. I have a PCV system) could be coming out of (some or all of) three places:

(1) the crank seal
(2) the timing cover gasket
(3) the sump pan gasket.

The sump pan gasket has been over tightened by a PO in the past and was lathered in grey silicone before fitting (!)

I have new sump pan bolts set from From the Frame up, taps of the correct thread pitch if needed, speedi seal 99138, a new sump pan gasket with the square teflon impregnated material, new timing cover gasket and the Moss lip seal 120-750.

I made a composite file of about every opinion and advice on installing new seals. I am, of course, now confused. Some say - stay with the original type seals and others have had success with the Moss lip seal. On the TF I will remove the radiator and raise the car on the hoist, so access is fine.

I have fitted the 'rope' type seals in the past to my early MGA with success but the modern lip seal seems fine also if fitted and aligned correctly.

Do either of you have a preference?

Many thanks Merv
M Hyde

Merv

I have used the Moss seal in their overhaul sets without issue. I set the seal with Ultra Black Permatex. If your oulley has grooves or wear install a speedi-sleeve I haven’t seen gasket sets that still offer the original rope seals. Lip seals will give better service life. When installing the seal in the cover it is important to center it on the pulley and make sure the seal is square to the crankshaft so it will run true on the pulley. Let the sealer set up overnight before installing the oil pan. Also now is a good time to install thread inserts of your preference into the bottom holes in the timing chain cover. These aluminum threads are notoriously weak and pull out. Use sealer on the bolts for these locations when installing the pan.
W A Chasser

Many thanks Bill. I thought that I had responded ... I am inspired with more confidence in the lip seal now. I have read and re-read the Moss instructions on this and they seem quite comprehensive. I will need to order some new gaskets for the water pump and so on.

Once I have the pan and timing chain cover on the bench I can do the cleaning of any old material and follow the Moss re-assembly sequence. As you say, centering is the key. I do wish that there was a decent set of images or even a video of this process!
M Hyde

One quick question - I received a new sump pan gasket and it is a cork one. I can see that the one on their new is also cork. However, on some 'sites I seem to see a paper gasket for this purpose? Is one correct or better? Motor is a 1500.
M Hyde

In the T Register "Stripping and Rebuilding the XPAG engine", they discuss putting a small cut in the bottom of the timing cover crankshaft lip to allow oil to drain back instead of setting against the seal.

I did this on my front seal installation and it has not leaked. I can't say the cut makes a difference, but it also has not hurt.
Bruce Cunha

Where does that cut go Bruce? In the inside lip of the timing cover at the rear, where the seal sits? With a Viton lip seal there would be silicone sealant in there I thought?
M Hyde

I have machined my timing cover/sump to enable a seal to be pressed in from the outside. I can now replace the seal without removing the sump.
I think a US member on this site had a boring tool that was loaned out.Do not forget to have the compressed gasket in place before boring.
Lip seals are designed to run wet or flooded so a drain should not be necessary.
Ray TF 2884
Ray Lee

Thanks Ray. At still stage I won't bore out the seal housing. Although the prospect of being able to replace a seal without sump pan removal is attractive! Any view on the cork v's paper sump pan gasket. Given that the cork one is much thicker, could this increase the gap between the seal housing grooves in the 'pan and the timing chain cover?
M Hyde

I think Gene Evans created the cutter for the seal. Mort Resnicoff wrote up a good bit about using it. Bud
Bud Krueger

I've used several of the modern seals without issue. I always use Right Stuff in the grooves before fitting.
Steve Simmons

Thanks Steve.

Is there any view on this question or is it a figment of my imagination?

"Cork v's paper sump pan gasket. Given that the cork one is much thicker, could this increase the gap between the seal housing grooves in the sump pan and on the timing chain cover?"
M Hyde

If the cork is thick then it may cause issues with a modern front seal by making the hole oval. This is purely guessing on my part, as I've never tried one. I don't like the cork being offered today because oil seems to weep through it far too easily. When I'm forced to use a cork seal, I like to coat it a very thin smear of sealer to make it less permeable.
Steve Simmons

My view as well thanks Steve. Looking at the current one fitted (cork) it has to ovalize the hole for the seal.
M Hyde

Merv, I am with Steve - check for ovalness of the area around the crank by temp fitting cork and paper gaskets.
My YT XPAG engine has been line bored and the crank is not central at the front or rear. I have fitted a speedi sleeve at rear (and drip tray) and fitted a lip seal at front which is now leaking - I have a spray of oil on the inside of the lower left bonnet flap after each run, so I am now looking at making a cutter to cut the aluminium timing cover and sump so I can fit a better fitting seal.

As my YT is in the shed (3km away) I haven't looked at it for a couple of months due to O/sea travels. I am therefore unable to say if I fitted a cork or paper sump gasket.

cheers
Stuart

Stuart Duncan

Ta Stuart. I was going to do a bench assembly and also an on-car trial assembly beforehand. I have both the Moss seal and the square section Teflon ‘rope’ type seals. Both have their ardent supporters and that makes it all the more challenging as I want to do this once! I have virtually no rear leak at all since fitting the PCV system and only a small front seal leak that seems associated with a PO over tightening the sump pan bolts and distorting the cork seal. I could just live with it, but I think it’s time to do it.
M Hyde

I have started replacing the front (and rear) crank seal. I will use the Moss lip seal. Radiator out, timing cover off and sump pan off. I have all the necessary gaskets.

Question: My crank pulley looks reasonably new but has a few circular/radial grooves that I could polish off. However- the recommended 99138 SKF Speedi sleeve that I bought seems far too small. This sleeve has a range of 34.423 - 34.958mm. My crank pulley (below) is very close to having an 36mm outer shaft diameter (1.414"). The Moss seal seems to fit over nicely the crank pulley shaft.

Before I buy another larger sleeve, am I missing something?


M Hyde

99146 for your 36mm pulley 99138 for the earlier 35mm scroll type---
But, your pulley looks fine, I'd give it a polish up and run with it as is--------
William Revit

I was think that it didn't look too bad and with some polishing ... Thanks again Willi. I really want to do this once. The timing gear looks great also and there was a new tensioner fitted and a new chain I believe.

Now to get that sump pan off for cleaning and flatness checking. There was so much sealant on it that it is stuck on and will need persuasion. The T9 gearbox bell housing makes the job more difficult too.
M Hyde

You young blokes and your modified cars--lol
William Revit

Ha Ha. We try Willy.

Oil Throwers? One thing I have noticed was the oil thrower/slinger was on backwards. It should be concave towards the front of the car. I also noticed that it is (only) about 48mm in diameter. Some other models (later) have a larger thrower with a diameter around 66-70mm. Is there any advantage in going bigger?

M Hyde

Probably lucky it was small in a way-Fitted the wrong way round like that, if it had been larger it'd have been getting mixed up with the chain---But yeah around the wrong way you'd think it would be guiding the oil down into the seal area where you're trying to keep it away from--A larger diameter slinger that rolled forward towards/over the bulge of the front seal housing would have to be an advantage you'd think, but you'd need to check that it cleared ok--as you would
Maybe an MGB style one but fitted back to front as compared to MGB

willy
William Revit

Thanks muchly Willi. I think I will stay with this one - oriented the right way. I now have everything ready to start on the installation of the new (Moss) seal. Tested on the bench and it all lines up correctly. Fingers crossed!
M Hyde

It is some time since I sold my TF but I do remember the seal I purchased from a T Series suppler was a loose fit on the pulley. I eventually turned a whisker off the pulley stub to provide a smooth surface and had no trouble buying a lip seal from Brammer to suit. 34m/m id rings a bell but I could be totally wrong. I did use RTV sealant which is far better than silicone but very expensive - 35 pounds a tube.

Jan T
J Targosz

Thanks Jan.
M Hyde

I should close this off. The car had a long drive today to test for any residual oil leaks (or coolant leaks) after the re-fit. The glass of Shiraz can be raised, thus far!

No leaks and oil pressure stays between 50 and 60psi. Oil pump re-priming was necessary as part of the job and I used a small pressure bottle and hose to pump oil in through the brass nut/valve on top of the pump until I could see oil coming out of the rockers when the motor turned without plugs.

The new front seal and pan gasket have settled in nicely with new bolts from FTFU and the lip seal as well. I used the Permatex Ultra Grey on Willi's suggestion. I do, however, know that old MGs are never entirely leak free, but this is the start I was looking for. I also fitted the MGB 7 blade fan that I had.
M Hyde

This thread was discussed between 15/01/2023 and 28/11/2023

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