Shell Spirax 90 EP

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ToyTrainGuy

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Shell Spirax 90 EP is specified for the trans, rear, & rack of our cars. No longer available, does anyone know what a good substitute is? Looking on the Net, I see all kinds of info about not using GL-5 lubricants (attacks brass), or like Redline MT-90 is not designed for Hypoid gears, etc. I'd like to change the fluid in my stock rear end & also my steering rack without doing more damage down the road by not using the correct lubricants. Anyone know what the best replacement is for our cars? Thanks!
 
Greetings

Hi Clark - it has been a while - I now own Frank Pinner's Mark II in addition to my Mark I. What is your email and I will send you some pix and catch up.
bill.bulpitt@urs.com.

Bill Bulpitt (Atlanta)
 
spirax

toytrain,
spirax 90 is a product dating back to the 60's when gear oil was not a mutiweight. there is now a spirax 80/90 but don't use it in your trans. the EXTREME PRESSURE additive used now in conventional gear oil is a sulfur/phosphorus compound and it attacks what we refer to as yellow metals. the sulfur is what makes it smell so bad. once the corrosion starts there is no way to reverse the reaction. most of the older trans used a single viscosity engine oil. alpines used a 30W engine oil. engine oils do have an exreme pressure additive but not something that will affect the syncro rings. you can use the conventional 80/90 in the rear end but if you have a posi you need the additive with friction modifiers. there are many new lubes on the market for use in units subject to very hard use and they do have a different extreme pressure additive. i would suggest a 30 in the trans and conventional 80/90 in the rear. that's what i use.
 
ToyTrainGuy,

65beam's suggestion to use 30 wt. engine oil in your trans when you are asking about modern equivalents to the original 90wt. gear oil Rootes recommended may be confusing at first.

Actually engine oil and gear oil wts. are different. A 90 wt. gear oil is really equivalent to a 40 or 50 wt. engine oil as to viscosity. See http://ecomodder.com/forum/showthre...ansmission-efficiency-metro-owners-128-2.html for a chart.

FYI, Redline makes a 75w/80 NS gear oil which meets the GL-5 standards, but is also syncro friendly. Must use a different EP additive than most. The product description on their website specifically mentions it is recommended for Ford Toploaders. No affiliation.

Gene
 
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Slippery Oils

In the tranny's, we've had good luck with plain NON-SYNTHETIC 75/80 NAPA, & others as available over the counter. Straight non-detergent 50W also is fine. CAUTION: Some of those synthetics will slick up the syncros enough to deter proper "blocking" and ruin a shift.
 
spirax

a GL-5 spec is for oils being used with hypoid gears and mainly applicable to axles. normally it is used with axle gears subjected to high speed shock load and low torque and low speed / high torque. there are a few manual trans that may call for a GL-5. it also is the only spec that meets MIL specs. i suggested the 30W oil since i have too many years around alpines. i only suggest a 50W oil in heavy duty truck trans and most of the time i suggest a synthetic oil for them due to the heat range. an oil meeting GL-4 spec is usually used in manual trans. oils can be very confusing so we verify what is in use and then recommend what to use based on manufacturer specs.
 
Thanks for all the replies & info. As soon as Bill Martin's 5-spd kit is available to the public I will order one, so I am not concerned with tranny fluid for my top-loader at all. Only concerned with proper rear-end & steering rack. I called Shell Oil wh told me not to use a GL-5 as it would attack the brass components of the rack, only look for GL-4 in Pennzoil, but alas I could not find that either! I have had great luck with Redline tranny lube in my Datsun 510 (it saved an expected rebuild), amazing stuff. I saw a disclaimer on Redline that their MT-90 was not correct for the hypoid gears in our rear, so I called Redline & they suggested to use their 75W90 GL-5 with special additives for brass in both the read & the rack as one of you guys suggested. So I guess that is the answer? Thanks again.
 
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