Jump to content
Sign in to follow this  
d2alfa

TR4a Engine Rear Crank Oil Seal

Recommended Posts

Hi Folks,

After delaying things for some time it now appears that I will have to solve the problem of oil leakage.

Unfortunately I do not have the necessary equipment to lift out the engine to get at the crank shaft and install a new oil seal.

Any idea of the cost of getting it done at a garage?

What other bits should be replaced while the engine is out?

Your comments will be welcomed.

Regards

David

Share this post


Link to post
Share on other sites

What sort of leakage amounts are we talking about ? do you realise it's a scroll oil seal that only works when the engines going ?

 

Mick Richards

Share this post


Link to post
Share on other sites

Hi Mickey ~

 

Here's the Mad Marx oil seal I fitted to my 3A. Very easy to fit and doesn't require the original scroll seal to be removed

thereby you end up with two oil seals!

 

Tom.

 

 

DSCF0232 - Copy.JPG

Edited by Fireman049

Share this post


Link to post
Share on other sites

Hi David,

as per Micks reply plus how much oil do you put in the sump.

It does not need to be up to the top mark. Perhaps keep it nearer the bottom mark and monitor it.

 

If you think the scroll is leaking excessively how do you plan to stop it. The Mad Marx lip seal works a treat and does not need the crank machining.

 

Costs will vary up and down the country depending on rates and hourly pay. But you must be getting close to £1500-£2000

 

With the engine out look at the clutch/fork/taper pin. Is the GB front oil seal leaking?

In fact with the engine out and the crank moved away look at all the bearings - could be a full rebuild

 

Roger

Edited by RogerH

Share this post


Link to post
Share on other sites

Hi,

Thanks for the replies.

The engine has leaked about 3 litres (top to bottom of dip stick marks) in about 300miles.

It drips when running and after running.

When stationary for a period, dripping stops.

The Mad Marx lip seal sounds the optimum solution.

David

Share this post


Link to post
Share on other sites

Hi David,

not sure about 3 litres between top and bottom mark possibly nearer 1 litre.

The scroll seal tends to not leak when driving. It certainly can drip when stationary.

 

Are you sure there are no other leaks pretending to be from the rear seal?.

 

Roger

Share this post


Link to post
Share on other sites

The TR engine is a mighty pump, if it doesn't have good breathing either from the block breather positioned below the fuel pump pointing downwards (early TR4) or the PCV valve (late Tr4/4a) it will blow oil out from handy holes, the crankshaft oil seal is very handy ! Check for oil leaks or heavy breathing when you remove the rocker cover fill cap, is it heavy breathing ? If so check the PCV valve for blockages and sort out.

 

As Roger says the rear scroll oil seal is a scavenge system.

 

A crude thread form is machined into the alloy rear 2 piece oil seal, this mimics a similar form formed into the dia of the crankshaft. The seal is movable a small amount in and out away from the crankshaft surface and is positioned by using mandrel (an accurate dia dummy crank about 6" long). It needs to be positioned carefully so the seal skims the crankshaft surface by no more than a few thou clear of it so that it "skims" the excess oil from off the surface having it travel along the rough thread form away from the rear main bearing and dumped into the sump.

 

I presume the engine was assembled before you bought it and so you will have no idea how the scroll seal was set. Considering how crude the seal system is it amazingly works remarkably well, without surfaces touching the oil is removed and even if left for decades will work as effectively now as it did 50 years ago. However...if the scroll seal was set using a mandrill made to the workshop manual unfortunately the dimensions given the for the mandrel are wrong (can't remember how much from memory but probably within 5 thou big I think ) this allows too much oil to remain on the crank and it makes its way to the outside. It could be that resetting the scroll seal if it is mis set would greatly reduce the oil spillage, however even in perfect condition a TR will occasionally drop some oil when stood and the engine turned off, because the scroll can't work without the engine turning, so it seeps through.

As Tom says the Mad Marx lip seal is the optimum solution, handily being positioned to the rear of the scroll seal and working whether the crank turns or not.

 

Depending on how handy you are you could revert to " days of yore" Art of TR Coarse engineering fix number 4. " How to replace your broken TR crankshaft at the side of the road".

From memory you'll find the method in the TR Technicalities CD ( I believe members are still sent one when joining, contact the office if you haven't one) section A7 page A-64. You'll find it tedious but back in the day when TRs were most peoples only car roadside replacements of many parts was done. The method could be used to remove your crank and refit with the engine in situ and the scroll seal reset in position and a Mad Marx seal fitted, a lot cheaper than having a specialist remove engine and refit.

 

Mick Richards

Edited by Motorsport Mickey

Share this post


Link to post
Share on other sites

+1 for Mick's response and the Mad Marx oil seal deals with the issue if fitted correctly.

 

but....

Are you sure it is not the rocker cover gasket? Gives precisely the same oil drip under the car. Ask me how I know?

 

Cheaper to fix too.

Peter W

Edited by BlueTR3A-5EKT

Share this post


Link to post
Share on other sites

The other question is does the engine have any method of breathing as not long ago I had one turn up that was leaking oil everywhere and turned out to have no block breather and no rocker cover breather!

Stuart.

Share this post


Link to post
Share on other sites

Thanks Guys,

Yes the car is now 50 years old and has been with me for the last 13; therefore I have no idea how the scroll seal was set (Mick).

I got the leakage completely wrong and 1 litre is correct (Roger).

No obvious signs of leakage from the top part of the engine.

Will check the PCV valve next.

Thanks for the information re TR Technicalities CD (Mick).

David

Share this post


Link to post
Share on other sites

The breathing from the rocker cover appears ok.

Would there be less internal pressure if a TR4 breather pipe, near the fuel pump, was installed?

Share this post


Link to post
Share on other sites

It is also possible that the engine has been rebuilt in the past incorporating the Landrover type seal which may have now failed.

 

This modification has been around for a long time now (over 30 years?)

 

Cheers

 

Graeme

Share this post


Link to post
Share on other sites

The breathing from the rocker cover appears ok.

Would there be less internal pressure if a TR4 breather pipe, near the fuel pump, was installed?

If you have PCV Valve then you wont need it but if you dont then best to fit.

Stuart.

Share this post


Link to post
Share on other sites

Originally the rocker box pipe was lead through the PCV to the inlet manifold.

However I fitted a brake servo and used the tapping in the inlet manifold.

The rocker box pipe now discharges to the air filters similar one of the designs adopted for the TR4.

The fumes appear to be travelling from the rocker box to the air filters but there are traces of oil also going to the filters.

Share this post


Link to post
Share on other sites

The other question is does the engine have any method of breathing as not long ago I had one turn up that was leaking oil everywhere and turned out to have no block breather and no rocker cover breather!

Stuart.

Stuart - is a rocker breather enough on its own? Presumably so as that's what most 60s cars had. JJC

David - I've been chasing an oil leak for some time, not as big as yours but too big to ignore. Turns out it was most likely to be the sump gasket. JJC

Share this post


Link to post
Share on other sites

I have had, what I believe is the rear oil seal, leaking since I purchased the car around 11 years ago. The loss of oil is around 1 pint every 800 miles & the drips into my drip tray have been consistent for that time. I have always taken the attitude that it will all get attended to when the engine has to come out it for something else. I have also taken the attitude that I am replacing with fresh oil on a regular basis, when the oil on the dip stick drops below the halfway mark!

Shortly after getting the car I was told that a TR has around 16 locations where they can leak oil! As I have about 2 or 3 I reckon I am doing ok despite the pesky thing leaving its mark when I park!

A great explanation by the way Mick, as usual!

Cheers.

Share this post


Link to post
Share on other sites

I have had, what I believe is the rear oil seal, leaking since I purchased the car around 11 years ago. The loss of oil is around 1 pint every 800 miles & the drips into my drip tray have been consistent for that time. I have always taken the attitude that it will all get attended to when the engine has to come out it for something else. I have also taken the attitude that I am replacing with fresh oil on a regular basis, when the oil on the dip stick drops below the halfway mark!

Shortly after getting the car I was told that a TR has around 16 locations where they can leak oil! As I have about 2 or 3 I reckon I am doing ok despite the pesky thing leaving its mark when I park!

A great explanation by the way Mick, as usual!

Cheers.

Forgot to say that I have good breathing courtesy of the Racetorations catch tank system. Appears to work well on both my cars.

Share this post


Link to post
Share on other sites

I too have the Racetorations catch tank which does do the trick but despite that I still used to have leaks from all directions, just had the engine out for rebuild and we do seem to have cured most, one of them (and its one we have come across a few times) was due to a slight bend on the front engine plate, only noticeable when the engine was out and not spotted on its first build 25yrs ago.

Stuart.

Share this post


Link to post
Share on other sites

Hello My first time iam needing some advice, I have a tr4a that has not been on the road for 41years its in really good condition i have had the engine and gearbox out to paint the engine bay,so I took a look at the clutch brand new just stuck  to the fly wheel any way today i was hoping to put the engine and gearbox back, 

Engine on crane tilted at 45 degrees oil spilling out from the bell housing when I separated the box from the engine first time no oil in the bell housing it's been dry for the last 3 years no drips.

Hope you can help

Yours Tr4a Pete.

Share this post


Link to post
Share on other sites

Hi Pete,

tilting the engine down at the back will allow the oil in the sump to flood around the rear crank bearing and the rear oil seal.

As mentioned in the old posts the scroll rear seal really only works properly when spinning around.

When the engine is not rotating there is no mechanism to stop oil flowing from one side to the other.

You obviously know how to take an engine out so don;t panic. Put it all back together and see what happens.

When you had the gearbox off the engine did you fit a new tapered bolt for the clutch fork/shaft. Did you also fit an extra pin at 90' to assist the feeble taper pin.?????

 

Roger

Share this post


Link to post
Share on other sites

As Roger said. Stricto sensu this is not a seal but only a drain. It should be called Rear crank oil drain.

Edited by Geko
spell

Share this post


Link to post
Share on other sites

"Stricto sensu" ... love it, which other car forum exists where you can stray into Latin and have people understand what you mean.

Mick Richards

Share this post


Link to post
Share on other sites
3 hours ago, Motorsport Mickey said:

"Stricto sensu" ... love it, which other car forum exists where you can stray into Latin and have people understand what you mean.

Mick Richards

Probably all fora of latin culture which is about a quarter of the world B) 

Share this post


Link to post
Share on other sites
2 hours ago, Geko said:

Probably all fora of latin culture which is about a quarter of the world B) 

'ita vero'...if you say so.

Mick Ricgards

Edited by Motorsport Mickey

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.