steering box lube?
 

I have a leaky zf steering box Top seal ring, 90011300450:.. 1961 "B" .... It drools 90# ... I read some were that it was possible to replace the 90# oil with grease.... Anyone ever try this??? Also .... how difficult is it to pull the seal. I have no problem taking apart the steering wheel and column. thanks for any feed back.... bob

I've done it, but I have the earlier VW type steering box. I was concerned that I wouldn't be able to pack the box with a very thick grease well enough to get to all the wear surfaces. So, I thinned / mixed the grease with some 90 weight in a baggie until it was thin enough to flow but still thick enough that it wasn't going to leak (as badly) out the seals.

Can't speak to your degree of difficulty question for replacing the seal on the ZF box.

Good luck.

Thanks for your experience Jeff .... Thinning the grease is a good idea .... maybe a heat gun on the box to help it flow into nooks and crannies ....The box is in great shape, other than the drool.... If I can find out about pulling the seal without removing the box I will likely replace the seal in place. bob












1961 Roadster 1966 9/12 2005 987 Boxster S

Here's what you need... "Lubriplate Aero", a 14oz can is plenty. It is one of those very very light high density grease that will occupy the shape of the container - no air locks. Ask me how I know...

I'll bite ..... How do you know Miguel ..... bob

I filled the box with 140# and the steering "felt" fantastic. Drove on twisty, bumpy road.... I wonder if the lubriplate aero would "feel" too heavy. I realize that would be a subjective question..... How about you Jeff ... What was the experience like with your "mixture" .....bob

I'm impressed... here we go... I've had several P-cars through out the years including 356s, actually have a 64C, a 930 and a 987S... anyway, instead of rebuilding the steering box (which I've done once and still dripped after all) I've tried the 90W the 140W I went as far as using STP oil treatment in one of the cars and never stopped "sweating"... of course I tried light grease but it "bridges" over the spur gear with time... one day at a Porsche Parade, in Maine, this "finding" (Lubriplate Aero) was discussed among the outlaw guys because the purist would never do something like this... so, I tried it then and really liked it; and I just did it on my 64C. I highly recommend it FWIW.

Bravo Miguel ............ Did it stop leaking? I imagine it's maybe viscus enough that it might "sling" rather than drip. But not too much of a mess? How much /if at all did the steering wheel feel heavy verses your experience with 140#???? This would be great news for me because the box feel very good and the car is perfectly aligned and set up..... Perhaps now I need to figure a way to empty the box..... thank you bob

Yes, it stopped leaking, and the steering feeling is just pure 356 with no play. I used a catheter size syringe with a 3/16 tubing extension to suck the box dry and refill it with the Aero from the bottom up. It is thick - very peculiar density - but it flows thru it "slowly..." Not messy at all - if ur patient & careful AND much much much easier than rebuilding the box.

However, if the 140 worked for you and it doesn't leak anymore obviously leave it alone. Did it?

If as you say, the more dangerous it is for my device

Yes Miguel It still drools. It drives and feels great, but I will fill it with the grease. Thank you for your experience..... I will follow your procedure. Start from bottom and slowly fill. P.S. I did not empty the box before adding the 140#. It was very low. So I can not say that a box filled with 140# would leak..... bob

John Deere corn head grease works well.
"Corn Head Grease
Thins to gear oil when working; thickens to grease when resting.
Factory fill for all John Deere corn heads"
https://jdparts.deere.com/partsmkt/document/english/pmac/8180_fb_GreaseSpecialMultiPurpose.htm#_Special-purpose_corn_head

It won't separate and leak past seals when it's cold, but heats up locally and acts similar to 90 wt when it is warmed by friction. It's being used by a lot of antique car owners for just the problems you stated. I've used it in other applications with great success. Fortunately my 356 steering box seals are still holding.

WDFIFTEEN .... Interesting stuff. I watched the video .... I wonder if since the worm gear does not always move that much that it may not create enough heat to make the steering not feel stiff..... Anyone ever try this grease in a 356 steering box? bob

^^
Not specifically a 356, but I have it in my '47 Dodge truck. I can't tell the difference, except there is no weeping of oil out of the bottom seal any more. It's used by a LOT of people with old cars of many makes and models, but no, I don't know of anyone who has specifically used it in a 356.

I just ordered both John Deer corn head grease and Lubraplate Aero grease. The Corn Head will get here first and I will install it to see how it feels...... bob

just stumbled across this very interesting topic. I'll be interested in your experience as my '58 (w/ updated ZF box) is in the same leaky condition.
thanks for the tips.
jerry

The Lubriderm Aero wont be here until Wednesday .... I have decided not to fill the box with the John Deere corn head lube. I want to look at both greases side by side before putting in the box... bob

results
 

Ok.... I stirred the aero grease and there was at least twice as much drag compared to stirring the john deer corn head grease. Also, the aero grease clumped like cottage cheese and there were air pockets . The corn head grease appeared more "liquid" even thou it would not spill if turned upside down. It was an easy decision to install the john deer corn head grease. The road test was excellent. fantastic feel at the wheel. Drove it on bumpy country windy roads. I checked the shaft for leakage and there was a pea size glob of lube. I believe that this may be the residual lube that was in suspense the bearings and such that will eventually work its way out leaving the Corn head grease. bob.........;)