Diff ratios

Technical advice Q&A

Piscator
Posts: 34
Joined: Thu May 30, 2013 8:08 pm
Location: Wirral
Great Britain

#21 Re: Diff ratios

Post by Piscator » Mon Dec 18, 2017 9:35 pm

Hugo,
In your post 13, I think you may have transposed the numbers so that the actual revs at 80mph with the 2.88 diff should be 2950. If I am right, it is surprising to me how little difference there is from the 3.07.

Cheers
John
John L

1969 S2 OTS RHD

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
Hugo
Posts: 1263
Joined: Mon Aug 29, 2016 11:16 am
Location: Horsham West Sussex
Contact:
Great Britain

#22 Re: Diff ratios

Post by Hugo » Mon Dec 18, 2017 10:20 pm

You mean this from #11; "my book gives 2,780 rpm @ 70mph with a 3.07 diff, and 3,150 @ 80mph. I reckon that a 2.88 diff will run 70mph at 2,430, and 80 @ 2,590."?

Yes you are quite correct - in fact that is not my only error. I'm not sure which is right & which is wrong now!
If the figure of 2,780 @ 70mph is correct for a 3.07 diff, then a 2.88 diff will give 2,600 rpm, not 2,430 as I previously stated. And if the 3,150 @ 80 mph is correct with a 3.07 diff, a 2.88 will give 2,950, as you correctly point out.
The difference between 2.88 & 3.07 is roughly 6%
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Series1 Stu
Posts: 1639
Joined: Thu Feb 02, 2017 12:26 pm
Location: Shropshire
Great Britain

#23 Re: Diff ratios

Post by Series1 Stu » Mon Dec 18, 2017 11:09 pm

Hugo wrote:
Mon Dec 18, 2017 7:47 pm
Well, the selector forks will be sitting in the hubs, and one hub will always be in contact with a gear. In first gear the 1st/2nd hub will be pushed backwards against first gear; if the gear moves forward under load because of excessive end-float, it will push the hub forward and the lever backwards. N'est-ce pas?
Like I said, "unless there's excessive wear in the gearbox".........
Stuart

If you can't make it work, make it complicated!

'62 FHC - Nearing completion
'69 Daimler 420 Sovereign
'78 Land Rover Series 3 109

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
Hugo
Posts: 1263
Joined: Mon Aug 29, 2016 11:16 am
Location: Horsham West Sussex
Contact:
Great Britain

#24 Re: Diff ratios

Post by Hugo » Tue Dec 19, 2017 12:17 am

Well that is exactly what I was saying, isn't it! That James might have too much end-float on his mainshaft, causing the gear lever to move backwards & forwards as the load reverses.
Also you said that during normal running "The selectors should be nowhere near the gear clusters". If you normally run in neutral I suppose that might be correct; otherwise it is not.
Come to that, I'm not entirely sure what you mean by 'gear clusters'. I was referring to the mainshaft gears. The only gears normally referred to as 'clusters' are the layshaft gears.
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Series1 Stu
Posts: 1639
Joined: Thu Feb 02, 2017 12:26 pm
Location: Shropshire
Great Britain

#25 Re: Diff ratios

Post by Series1 Stu » Tue Dec 19, 2017 1:45 am

I refuse to pander to pedantry.
Stuart

If you can't make it work, make it complicated!

'62 FHC - Nearing completion
'69 Daimler 420 Sovereign
'78 Land Rover Series 3 109

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

politeperson
Posts: 1290
Joined: Tue Jun 07, 2016 8:26 pm
Location: Boston UK
Great Britain

#26 Re: Diff ratios

Post by politeperson » Tue Dec 19, 2017 3:20 pm

I think the main difference between a 3.07 and a 2.88 (apart from 6%) is that I can go out and purchase a 2.88 tomorrow. A s/h 3.07? not so sure I have seen one for sale for a while.

Wear on my gearbox mainshaft? I don't think so Hugo.
Its true, but Enzo never said it
Too many E types
XK120 SUs

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
Hugo
Posts: 1263
Joined: Mon Aug 29, 2016 11:16 am
Location: Horsham West Sussex
Contact:
Great Britain

#27 Re: Diff ratios

Post by Hugo » Tue Dec 19, 2017 3:38 pm

Not wear - end-float. I wish I could say the same - my engine/gearbox ass.y is sitting on the garage floor where I can measure the mainshaft end-float on the output flange. It's about .020", give or take a bit. Looks a lot more, as these things always do.
I've only just started researching diffs, but my impression was that the 3.07 was more common than the 2.88. Maybe I've just been looking in the wrong places.
Right now I'm trying to decide whether to pull my gearbox to bits or pretend I'd never seen that end-float. At any rate, it looks like I shall have a 3.54 diff for sale in the near future. Might be of use to somebody with points on their licence?
While I'm on the subject, I have a lot of LHD stuff for sale for a Series II, from where I converted mine to RHD. Power steering complete, dash, throttle pedal arrangement etc. Also 2 Strombergs + manifold, & air-con complete. And that stupid charcoal canister you need in Ca. I even have a set of in & ex valves, about half of which are good, and used timing mechanism. Late Xmas shopping anyone?
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

Link:
BBcode:
HTML:
Hide post links
Show post links


64etype
Posts: 428
Joined: Sun Mar 20, 2011 2:07 pm
Location: Texas, USA
United States of America

#28 Re: Diff ratios

Post by 64etype » Tue Dec 19, 2017 5:11 pm

politeperson wrote:
Tue Dec 19, 2017 3:20 pm
I think the main difference between a 3.07 and a 2.88 (apart from 6%) is that I can go out and purchase a 2.88 tomorrow. A s/h 3.07? not so sure I have seen one for sale for a while.
I'm sure it has been mentioned previously, but the 3.07 gearset was common on DANA Model 44 differentials in old Jeeps and International Scouts (not sure how plentiful in the UK). I bought a ring and pinion from the front axle of a Scout as the front differential is not engaged all that often on part time 4WD units... so low wear. $25...like new. Rebuild parts and professional conversion of my differential was in the $600 range. Also, new DANA 3.07 gearsets are readily available from U.S. vendors...perhaps in U.K.? Very minor differences in bearings and seals are easily addressed. The attached link provides details regarding part numbers required. (Section IV)

http://www.dazecars.com/dazed/JaguarIRS1.html
Eric

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Barry
Posts: 515
Joined: Thu Jul 05, 2012 1:11 pm
Location: United Kingdom
Great Britain

#29 Re: Diff ratios

Post by Barry » Tue Dec 19, 2017 11:48 pm

No, this is not true about the Jaguar irs developed initially for the E-type and Mk10. It was designed by Bob Knight after William Lyons bet him £5 he couldn’t Design an irs unit in one month. Bob achieved it, then Norman Dewis developed it with the rest of the Coventry team. Now, the Ford irs I think was illuded to, was developed for the DEW98 platform for the likes of the Mondeo and X type in the late nineties. I hope this avoids any confusion.

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Barry
Posts: 515
Joined: Thu Jul 05, 2012 1:11 pm
Location: United Kingdom
Great Britain

#30 Re: Diff ratios

Post by Barry » Tue Dec 19, 2017 11:51 pm

.........and to add to my last post. Why would Jaguar ship Salisbury units to the USA and have the irs shipped back. It never happened, and in any event, in the 60’s nearly all American cars ran with live axles and cart springs.....

Link:
BBcode:
HTML:
Hide post links
Show post links


64etype
Posts: 428
Joined: Sun Mar 20, 2011 2:07 pm
Location: Texas, USA
United States of America

#31 Re: Diff ratios

Post by 64etype » Wed Dec 20, 2017 8:50 pm

I have no idea if assembled differentials or internals (certainly not the complete IRS??) were ever shipped from the U.S to the UK. But this did pique my interest regarding the "Salisbury" connection. And from what I was able to find, Salisbury was a U.S. wheel manufacturing company that was purchased by Spicer back in the early 1900s. The term Salisbury is used in regard to a type of axle design configuration, not a place. From what I could find, the E-type center section was a Dana-Spicer UK product. No idea where that foundry/production facility was located. I'd be very interested in this bit of history if anyone has information. Maybe I missed it in the technical data section....
Eric

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
Hugo
Posts: 1263
Joined: Mon Aug 29, 2016 11:16 am
Location: Horsham West Sussex
Contact:
Great Britain

#32 Re: Diff ratios

Post by Hugo » Wed Dec 20, 2017 10:43 pm

Strange - my last two posts here seem to have evaporated. Where did they go?
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

Link:
BBcode:
HTML:
Hide post links
Show post links


288gto
Posts: 1417
Joined: Wed Nov 14, 2012 8:59 pm
Location: United Kingdom
Russia

#33 Re: Diff ratios

Post by 288gto » Wed Dec 20, 2017 10:50 pm

For Eric and Barry , from Google...

The Salisbury Wheel Company was founded in Jamestown, New York, in 1901 when C.W. Salisbury, a key-maker and mender of umbrellas, patented an automobile wheel, then pooled his life savings with two colleagues, Scott Penfield and E.D. Sherman, and started manufacture. Salisbury's first customer was the E.R. Thomas company, maker of the Thomas Flyer. In 1905, the company started manufacturing front axles. Two years later rear axles were added to its product line.
Acquired by Spicer in 1919, Salisbury was moved to Toledo in 1929, closer to the center of the automotive industry. Salisbury axles became standard equipment in thousands of automotive vehicles. At the outbreak of World War II the light, Salisbury's rugged axles proved ideal for the Jeep. The Jeep proved so popular that in 1945 Salisbury had to build a new plant in Fort Wayne, Indiana. In 1970, the Salisbury Axle group was renamed the Spicer Axle Division.


Simon
Simon
1969 S2 OTS

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Barry
Posts: 515
Joined: Thu Jul 05, 2012 1:11 pm
Location: United Kingdom
Great Britain

#34 Re: Diff ratios

Post by Barry » Wed Dec 20, 2017 11:16 pm

I think you will find that all E-type Salisbury diffs were made in the UK by GKN, who bought the rights to manufacture. Furthermore, Maserati and others had Salisbury diffs made by GKN in the UK.

Link:
BBcode:
HTML:
Hide post links
Show post links


288gto
Posts: 1417
Joined: Wed Nov 14, 2012 8:59 pm
Location: United Kingdom
Russia

#35 Re: Diff ratios

Post by 288gto » Wed Dec 20, 2017 11:30 pm

Interesting stuff Barry, thanks.

A bit more research uncovered this great advert from 1962...

Image

And a bit more info on the "Salisbury" name.

"Salisbury Axle in USA was also part of the Spicer Group and in 1939 the Salisbury Transmission Company was formed in Britain to manufacture hypoid rear axles and, in the late 1950s, Powr-Lok limited-slip differentials."

As Barry mentions above they were then taken over in 1967 by GKN

Simon

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

PeterCrespin
Posts: 4561
Joined: Fri Mar 05, 2010 8:22 pm
Location: Gaithersburg, Maryland.
Contact:
United States of America

#36 Re: Diff ratios

Post by PeterCrespin » Thu Dec 21, 2017 1:55 am

politeperson wrote:
Mon Dec 18, 2017 11:03 am
My steering wheel is a standard 15 inch 3 spoke steering wheel.
If your Avatar is any guide James (SWB FHC), your steering wheel can be standard or 15 inch, but not both. Having said that, a 15" standard-style wheel is the nicest option of all for Series 1&2 IMO.

Pete
1E75339 UberLynx D-Type; 1R27190 70 FHC; 1E78478; 2001 Vanden Plas

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Barry
Posts: 515
Joined: Thu Jul 05, 2012 1:11 pm
Location: United Kingdom
Great Britain

#37 Re: Diff ratios

Post by Barry » Thu Dec 21, 2017 7:21 am

Brilliant, Simon, thanks for finding this. I knew the link, but could not prove the final details. I have nothing against our American friends, but the idea of either the irs, and or the components being either designed or manufactured in the USA was not right. That’s what is so good about this forum, someone always manages to “know” or find out the correct answer. Happy Christmas!

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
Hugo
Posts: 1263
Joined: Mon Aug 29, 2016 11:16 am
Location: Horsham West Sussex
Contact:
Great Britain

#38 Re: Diff ratios

Post by Hugo » Thu Dec 21, 2017 10:11 am

I think the bit I quoted in one of my 'disappeared' posts may have said it was 'developed' by Spicer or Dana or whoever it was in the US.
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

mgcjag
Moderator
Posts: 8070
Joined: Fri Jul 09, 2010 6:15 pm
Location: Ludlow Shropshire
Great Britain

#39 Re: Diff ratios

Post by mgcjag » Thu Dec 21, 2017 10:47 am

Hugo...your posts have not just disapeared..they were soft deleted and can be viewed if you click on them in the thread above.......I deleted the first as it was just a quote found on the net that was being proposed as fact....the second post had nothing to do with E types .....there is a pub chat or my dream garage area if you want to post about your other vehicles but it really is an E type forum..Steve
Steve
69 S2 2+2 (just sold) ..Realm C type replica, 1960 xk150fhc

Link:
BBcode:
HTML:
Hide post links
Show post links

User avatar

Topic author
Hugo
Posts: 1263
Joined: Mon Aug 29, 2016 11:16 am
Location: Horsham West Sussex
Contact:
Great Britain

#40 Re: Diff ratios

Post by Hugo » Thu Dec 21, 2017 11:10 am

The bit I quoted in my first post wasn't 'found on the net'. Not by me at any rate. I was quoting from an article mentioned by the previous poster. And my post spawned a further seven posts expanding our knowledge of the origin of the IRS unit, Salisbury axles etc. Are you going to delete those seven posts also?
And my second deleted post was in response to this from Barry; "in the 60’s nearly all American cars ran with live axles and cart springs.....". I merely mentioned that I owned several American cars from the 60's with IRS and/or coil springs.
I suppose that comment will be enough to get this post deleted now?
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

Link:
BBcode:
HTML:
Hide post links
Show post links

Post Reply Previous topicNext topic