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Grease nipple thread size and orientation?


1969Mk3Spitfire

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I'm putting my car away for its first winter in my ownership. Not sure whether to do it now or wait until it comes out of hibernation in the Spring, but, I've been looking at the maintenance schedule shown within the original owners handbook.

This refers to oiling/greasing 4 features.  I've located 3 of them.  I need to buy some nipples but not sure of thread size or best orientation for ease (in-line or 90 degree).

 

1. Oil the lower steering swivels. 

2. Water pump.  My water pump appears different to the one in the handbook picture and does not have a grease nipple plug. 

3. Steering rack, earth strap location.

4. Rear hubs.

 

I'd appreciate any advice / recommendations. Many thanks in advance.

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At some point during production the water pump was changed from a serviceable one with grease nipple to a sealed-for-life type without. There is no regular service task for the later type pump.

There are two common thread sizes for grease nipples. The trunnions and rear hubs are the small one, the steering rack is the larger.

Many years ago I bought myself a pack of assorted grease nipples - both threads, straight, right-angle and 45 degree - to cover all eventualities. I think the straight are usually easiest in rear hubs, angled are easier in the steering rack.

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And angled for the trunnions. Nipple covers are also useful, keep the muck and dirt out, although they do drop off, so buy a dozen!

grease.PNG.d2cbde84a1139d49b517b353ac6a7cc2.PNG

 

The first lot I ordered I got these, they're better, you can use the string to tie them on and they don't get lost.

 

tassle.PNG.fbd13340ab521562db2dd7ae9e115547.PNG

 

db

 

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Thanks to you both. It seems remarkably difficult to find definitive references but....are they....

"small one" 1/4 UNF. 28 tpi, od 0.25 in / 6.35mm

"large one" 1/8 BSP, 28 tpi, od 0.383 in / 9.7mm

Next on my list of confusing issues, parallel or taper thread for the BSP version?

Can anyone confirm?

 

 

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Those do appear to be the correct threads - they're the ones in this pack and, I suspect, this one, although that doesn't say. Whether the BSP ones are tapered isn't stated but the photos look like they are. It probably doesn't matter much - a straight one may not seal perfectly but it'll be good enough for lubrication and you'll be re-fitting the plug anyway because it holds the earth strap much better.

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Non member your previous post said the large nipple was used on the steering rack and you advise this is 1/8BSP tapered? Isn’t the rack earth strap fitted under this grease nipple or bolt head so surely it must be a parallel thread to go all the way into the rack housing and lock the earth eyelet

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11 minutes ago, Peter Truman said:

Non member your previous post said the large nipple was used on the steering rack and you advise this is 1/8BSP tapered? Isn’t the rack earth strap fitted under this grease nipple or bolt head so surely it must be a parallel thread to go all the way into the rack housing and lock the earth eyelet

That's true; when I refurbished a number of racks in the first lockdown the grease nipples were all straight and screwed in to the end.

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3 hours ago, Peter Truman said:

Non member your previous post said the large nipple was used on the steering rack and you advise this is 1/8BSP tapered? Isn’t the rack earth strap fitted under this grease nipple or bolt head so surely it must be a parallel thread to go all the way into the rack housing and lock the earth eyelet

No, wrong on two counts. First, I only said the ones available "look" tapered and that it doesn't matter much for greasing. Then I said "you'll be refitting the plug", because the hex on the grease nipple isn't large enough to properly hold the earth eyelet. The factory fitted a plug with a decent size head, and so should you.

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Sorry if I misread your post but it was 4AM here, the important thing we cleared up it must be a parallel BSP thread.

Ref the nipple not being able to hold the earth eyelet, agree it could be an issue BUT my Mk2 Vitesse has had a permanently fitted grease nipple with earth eyelet for the last 50 years and I've never had an issue, suppose it depends on the size of the hole in the eyelet, the strength of the eyelet some modern ones are very weak, and the across flat measurement of the nipple.

I modified my daughters Mk2 Spitfire with a permanent grease nipple & the standard Triumph earth strap 20 years ago when we got it and its always been OK too! In both cases I still have their respective brass plugs for prosperity came across them when searching for something else just the other day!

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The other grease nipple not mentioned yet is the long nipple for the UJ on the prop shaft (unless a sealed for life one is fitted) - I presume the Mk3 Spit has this requirement (my GT6 does)? If anyone has info on this it may assist the original poster?

Gully

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1 hour ago, 1969Mk3Spitfire said:

Thanks for the thought, Gully.

The owners manual makes no reference to prop shaft lubrication and my Autobooks manual says that they are packed with grease upon assembly.

 

 

Ever seen 40 year old grease? Yuck! Be a sport, make it's day and give it a fresh squirt.

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10 hours ago, Colin Lindsay said:

Ever seen 40 year old grease? Yuck! Be a sport, make it's day and give it a fresh squirt.

The car had had a body-off restoration completed just prior to my buying it so, I believe, that the shaft would have been greased upon reassembly. It’s only done less than 200 miles since. I’m gathering the various bits to enable me to service it when it comes out of hibernation in the Spring. The other grease points may or may not need a fresh squirt but doing the research is keeping me busy during house arrest 😀

I appreciate the help and advice.

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