Mazda MX-6 Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter · #1 · (Edited)
Anyone here run into problems changing the reair oil seal on a KLZE?

If you have changed the rear seal in your ZE, what's the part number you used?

I've just gotten my ZE in (and checked that it is a real ZE...) and changed the rear oil seal before I left the shop tonight. Long story short, I commited the cardnal sin of not really looking real close at the old oil seal before I removed it. After installing the new one I noticed that it doen't seem to fit correctely. The wipper lip (outer lip of the seal) doen't fit the end of the crankshaft. Anyone else notice this? Or are all the rear seals like this?

In short, I'm asking if the ZE uses the same rear oil seal as the DE. I can't find anythings that says otherwise, however I think it might.


Warning, the rest of this post gets a bit techincal. I should preface it buy saying that I'm a hydrualic mechanic and spend a good deal of my time looking at seals.

The old rear seal (presumably the original one) is a NOK BH3289G. NOK is/was an asian manufacture of seals. My new seal is a felpro# BS40387, which is listed for any vehicle that had a KL motors. Upon closer ispection I found that the "felpro" seal is actually made by an TCM and is a TCM 93x76x10STCL. Basically a TCM silicoln seal 93mm O.D., 76mm I.D. and 10mm height (or some might say thickness). (side note, TCM/ditchomatic is a well known maker of industrial seals. They been slowly expanding into automotive and other specialty niche markets by buying out old factories and thier manufacturing tooling from all over the world). It gets interesting in that the diameter of the surface on the crankshaft that the rear seal rides on is not 76mm, but 75mm. Mine actually measured 74.98mm, but it's a 75mm shaft.

The original seal (NOK BH3289G)was able to be crossed to a somewhat industy stanard number dimensional number of 29675. SKF, NOS, and CR seals would be a part number 29675. 29675 basicly denotes a seal with an ID of 2.992" OD of 3.662" and .394" or 76mmID, 93mmOD and 10mm H. The other part number that comes up is a BCA/National crankshaft oil seal #1019. This also crosses to a 29675. Basically every rear seal part number I can find for a KL motor describes a seal designed to seal a 76mm shaft. Why is everything listed a 76mm ID seal for a 75mm shaft? Is a KLDE a 76mm shaft or are all KL motors a 75mm shaft at the end of the crankshaft? I think the inner and actual sealing lip will touch, but not by much.

It really doesn't seem right. However, I can't really find an automotive type oil seal for a 75mm shaft. I know i can get a seal that will fit (75mmX93mmx9mmH,the difference in heigth won't matter at all) , but it will be a standard industrial oil seal lacking the groves on the inner sealing lip of automotive oil seals. The groves on the inner lip of automotive seals are designed to grab oil from the shaft and sling it away from the sealing lip. The is let's the seal reatain oil "not leak" even after subsutantial wear to the sealing lip and sealing surface. If I run an standard industrail seal, I lose the additional sealing these groves provide.

The other concern is the fact that the crankshaft spins to 7000+ RPMS. Most similar industrial applications (like hydraulic pumps and motors) spin far slower. If I run a stardard seal I know will fit, I'm not sure how long it will last. However, I'd hate to run what I have and find it leaks once everything is back together.

I figure there should be many other people who've changed the rear seal on their KLZE. What part number worked and has anyone else run into this problem?

Sorry if this a long post, but the more I try to figure out this rear seal, the less it adds up. It makes even less sense that my motor with it's 75mm shaft had a seal designed for a 76mm shaft and apparantly worked. I just wish I had looked closer at how the old one fit before I removed it and installed the new one.
 

·
Registered
Joined
·
32 Posts
Hmm when I partially rebuilt my engine I just got a KLZE head gasket set and a KL bottom end set and that covered all the seals including this one. The bottom end set was labelled as for the various KL engines, and fitted perfectly for my KLZE So from experience the KL main seals appear to be the same. I would just cough up and order from mazda/ford sooner than putting in an untested industial seal, it's not a fun place to get to.

This is the set I used:
Ford Probe Store - Ford Probe Spares/Mazda Parts/RocSpeed - UK & European Specialists for Ford Probe, Mazda MX-3, MX-5, MX-6, 626, Xedos & 323F, Spares, Parts, Modifications
 

·
Registered
Joined
·
137 Posts
I just replaced my main seal about 3 weeks ago, when i put in a new clutch. I used the Fel-pro seal and had no problems with it. I got the seal from Advance auto, and the part # was BS40387.
 

·
Registered
Joined
·
86 Posts
I used to be a manager at advance auto, good people at least around my way. Unless the box felpro box was ripped open, that should be the correct seal, those boxes all show up sealed on our doorstep. Maybe get them to open one for you just to double check. I used to open boxes ALL THE TIME to help people check things.

Good luck!! I am about to change the rear main seal in my DE when I do my clutch, and looking into getting a ZE this summer.
 
1 - 4 of 4 Posts
Top