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TR2/3/3A TR3 engine rear oil seal

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bluemiata90

bluemiata90

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I'm in the process of rebuilding my 61 TR3 engine and I need some input, should I have the rear crank seal reground to proper size and purchase the new and improved rear crank seal or if done correctly will the old standard seal work without leaking. If I read 3 different TR books, I get 3 different opinions. I'd like to hear from those that have some first hand experience. I'm leaning towards standard, due to cost factors, but if the overall opinion is the new and improved seal, I'll have to give it some serious thought. Also, one repair manuel states that you have to purchase a special tool to install the standard seal or you have a good chance of having a leak, is this true. /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/driving.gif /ubbthreads/images/graemlins/driving.gif
 
From most accounts, the rear seal will either leak immediately, or leak within a few thousand miles. It's just a bad design.

In most cases, new and improved is better...but as we know with repro parts for TRs, the new parts are often cheap and warp/disintegrate quickly.

I don't have any experience with the new and improved, but my original/rebuilt still oozes.
 
I changed to the new seal on my TR3 2 years ago and have not had any problems with this. I would rather have and rubber seal that can be changed easyer when there is a leak.


Don
 
Hi Don

I've got a leak from my rear oil seal on a TR4. The oil seal assembly is two aluminium pieces with a rubber seal inside, so I assume this is the uprated version. The rubber seal is cut and it appears that this has to be eased over the end of the crank. Is this what you did? How does it not damage the spring inside the seal? Also there was black silicone inside the grooves of the aluminiun pieces. Is this necessary?

Any help from anyone who has changed the rear oil seal would be gratefully received.

Thanks

Steve
 
If the rubber seal is cut put the cut to the top of the seal area. If the seal is not cut it can be slip over the crank end using a plastic bag and some dielectric grease or some engine oil. I do this all the time on aircraft engine crank seals.

Don
 
Steve, you have what I call a bugged up old seal. There was no seal inside those two aluminium pieces and no silicone. Those two pieces were designed to throw oil back into the oil pan and were not the best when new. I'm not sure but unless you pull the engine I don't know how you will get the new seal in as far as I can remember there is some machining that has to be done. A new aluminium seal is about $80 from Moss and they are difficult to get right, just follow the instructions and you will get as close as anyone. Should slow it down a lot and might stop it altogether. Good luck, Wayne
 
Steve, on doing a bit of checking, you may have the new seal and someone else already put it in, just did a bad job of it. You need to take what you have to a good TR dealer of even give us some pictures and with the help of the guys on the forum it should be no problem. If you decide you have the new unit just order the rubber seal part and do it right first time. Wayne
 
Moss sells the rear crankshaft seal conversion. It is a rubber seal that is held in place by two peices of aluminum and bolted to the block. The crank is needs some machine work before it can be installed. The new seal should not need to be cut to install.

Don
 
Hi all,

First post here (hijack alert)! Looking at probably doing this repair this winter. Will pull the tranny - suspect oil on the clutch disc is responsible for mild clutch chatter in first. Any tips to installing a new stock seal? Any "while I'm in there" repairs? I'll need a new clutch disc. The pressure plate / TOB have only about 10k miles on them, but I don't want to have to drop the tranny again down the road.
 
If you are installing the original type seal (scroll on the crankshaft and aluminum fittings with multiple grooves), Moss has the mandrel for aligning it as specified in the workshop manual. I replaced the original setup with a lip type seal a few years ago. The seal is split with the split installed facing the top of the engine. The spring has a hook and eye arrangement to go around the journal then pushed into the seal recess. The kit comes with aluminum housings that are assembled to the block and bearing cap same as the original; no mandrel is required. Steve, if you need the original instructions to replace the seal if it is the later style; I can send them to you. Mine is not leaking, well at least not at the rear seal.
 
Thanks for the replies. I'll take some photos of the bits I've got and try and load them on here later.

Steve
 
TRMARK, I have my engine and crank out and I have decided to go with the new seal conversion. My biggest concern is the machining. I've had major problems in the past with some machine work done locally. When I buy the seal, will it include instructions for the proper machining and how difficult was it for you to install the seal after the machine work was done. I don't want to have to pull the engine or trans for many years after this is done, so I want to do it right the first time. scott /ubbthreads/images/graemlins/driving.gif
 
The instruction will till you how much the machine shop needs to turn the crank down.

Don
 
Hopefully the pictures of the assembly and the seal are below. Can someone confirm that the aluminium housing is the later type?

TRMark could you send me the fitting instructions please? I intend getting the new bits this week ready to fit on the weekend. /ubbthreads/images/graemlins/cheers.gif

Thanks for all the replies

Steve

seal3.jpg


al3.jpg
 
Looks like what I installed in my TR4. The seal is available separately. I have Emailed my instructions to you. I am sure that you will receive instructions with your new seal, but this will give you a preview of the scope of the project. As a thought, you may want to check the diameter of the crank where the seal rides. The correct size from what I understand is 63.5 mm. I have heard of some instruction sheets stated it as 65.0.
 
The instructions will come with the seal. The machineing is very straight forward and will not present any problems to a competent engine shop. Check with the local gearheads for a referral. I know what you mean though, I had one of the local idiots screw up a grind on an Alfa. My habit is to mic everything before assembly.
 
[ QUOTE ]
The instructions will come with the seal...

[/ QUOTE ]

Not from personal experience but have heard that some instructions have you taking too much off the crank. You will probably want to double check (with someone here who has done this successfully) that you have the correct dimension or else get the part from a knowledgeable source.
 
If I remember right, before you install the seal portion, remove in spring that rides in the groove inside the seal and shorten it a bit. This exerts a little extra pressure on the sealing surface against the newly machined cranks for a more positive seal. (per Jack Drews suggestion). I don't remember the exact lenght to cut the spring but maybe someone else here does.
 
I've spoken to a TR repairer who suggests that the engine needs to come out to do the job properly. So I've ordered the bits ready for the weekend and will let you know how I get on.

Thanks for the many replies, much appreciated.

Steve
 
I just got my TR3 crank back from the machine shop. The 2 things that had to be done to the crank for the installation of the new rear crank seal are as follows:
1. The rear area of the crank that has the scroll has got to be machined to 63.5mm, so the new seal and aluminum seal holders will fit.
2. The rear lower main bearing cap has got to have 2 holes drilled into it at a specific angle, to allow for better oil return into the pan. The machine shop just followed the instructions that were send with the seal.
I had all this work done and the crank polished for around $160.00. As far as how it works, I really won't know till spring when the engine is back into the car. I hope this information helped.
 
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