« previous next »
Pages: [1]

Author Topic: Diff question for series and RRC type people  (Read 417 times)

Offline ArmyRover

  • Hero Member
  • *****
  • Posts: 1462
    • Email
Diff question for series and RRC type people
« on: April 01, 2009, 11:28:42 PM »
I have a line on two pairs of ring and pinion originally bought for a series non-salisbury.  Will they work in RRC diffs?

Also these are 4.70's, I know 4.11's will get me back to stock with 33 inch tires, how far off the map will the 4.70s put me on the rpms and loss of cruising speed if they will fit in the diff obviously lol?

Thanks in advance guys and gals
Logged
"I disapprove of what you say, but I will defend to the death your right to say it."  ~Voltaire

Offline SafeAirOne

  • Full Member
  • ***
  • Posts: 180
    • Zuni Racks
    • Email
Diff question for series and RRC type people
« Reply #1 on: April 02, 2009, 12:54:20 AM »
I had a newer 3rd member on the front of my '73 10.  It looked like this (note flat casting in bottom of diff that house the pinion oil galleries):
 

 
 
This is NOT a regular rover-type series differential.
 
I have since learned that this diff is the type used on coil-sprung rovers, but at the time I thought it was just a later version of a pre-rationalized rover-type diff.
 
I ended up replacing the ring & pinion gears in mine.  I ordered a stock series rover-type 4.7:1 R&P from British Pacific and installed it without difficulty.
 
Unfortunately, thinking it was just a newer rover-type differential, I ended up setting the pinion bearing preload perfectly for the WRONG TYPE of differential.  The pinion bearing brought this to my attention a few thousand miles later.
 
So the answer to your question is yes, if you have the type of differential pictured above, the regular series rover 4.7 R&P should bolt right in/on, just be sure to use the correct bearing/backlash setup for this type diff.
 
BTW, Teri Ann has VERY extensive Rover driveline calculations posted on her website here which will answer all your other questions.
Logged
--Mark

Offline Daniel

  • Hero Member
  • *****
  • Posts: 1280
    • http://www.x-trememarine.com
    • Email
Diff question for series and RRC type people
« Reply #2 on: April 02, 2009, 08:04:18 AM »
Your biggest issue would be the 10 vs. 24 spline issue. If you still have 10 spline axles under yours, you can go with the series diffs in the rover axle housings. But if you've already converted to 24  spline (which I thought you did?) you won't be able to use them. Even very late series III which were  24 spline outers, still used 10 spline inners in the front and only Salsbury's were 24 spline rear in series trucks. Once they went to coiler (Series III Stage I V8, and the 90/110 lines), they went to 3.54 diffs.
Logged
2002 LR DII SE Kalahari Edition. 4.6, locking CDL, and Detroits.
1994 LR RRC LWB. EAS conversion w/ +2" springs.
1968 LR SIIA 88" Hybrid, with 109" 1 ton axles SOA. Needs Tartis for completion.

1979 LR SIII 5 door 109 SW, 11 seater. Sold, 09'.
1997 Disco I Bobtailed buggy conversion. Sold, 11'.

Offline ArmyRover

  • Hero Member
  • *****
  • Posts: 1462
    • Email
Diff question for series and RRC type people
« Reply #3 on: April 02, 2009, 10:19:21 AM »
I'm not swapping the diffs themselves just the gears.  Which so far looks like it should work.  The only rough spot I'm finding from other boards is the fact that the 4.7 are weak gears i.e. break easy.

SafeAirOne, that looks just like a RRC third thanks for info and the link.
Logged
"I disapprove of what you say, but I will defend to the death your right to say it."  ~Voltaire

Offline Daniel

  • Hero Member
  • *****
  • Posts: 1280
    • http://www.x-trememarine.com
    • Email
Diff question for series and RRC type people
« Reply #4 on: April 02, 2009, 01:32:04 PM »
If you're just doing the ring and pinions, you shouldn't have any problems. The 4.7's are weak, even Bill at GBR only recommends using them if you get the cryo'd ones. The 4.11's are much stronger, and a cryo'd 4.11 is about the strongest you can get over here.
Logged
2002 LR DII SE Kalahari Edition. 4.6, locking CDL, and Detroits.
1994 LR RRC LWB. EAS conversion w/ +2" springs.
1968 LR SIIA 88" Hybrid, with 109" 1 ton axles SOA. Needs Tartis for completion.

1979 LR SIII 5 door 109 SW, 11 seater. Sold, 09'.
1997 Disco I Bobtailed buggy conversion. Sold, 11'.

Offline ArmyRover

  • Hero Member
  • *****
  • Posts: 1462
    • Email
Diff question for series and RRC type people
« Reply #5 on: April 02, 2009, 01:43:38 PM »
that is my hang up I would like the improved ratio but I don't feel like going through it all to have them bust under load...

I think I'll just wait and do the yota swap.
Logged
"I disapprove of what you say, but I will defend to the death your right to say it."  ~Voltaire

Offline Daniel

  • Hero Member
  • *****
  • Posts: 1280
    • http://www.x-trememarine.com
    • Email
Diff question for series and RRC type people
« Reply #6 on: April 02, 2009, 02:50:58 PM »
Bill; what tire size are you running? If 32 or 33, you'll be fine. If 34 or 35; I'd wait for the yota swap.
Logged
2002 LR DII SE Kalahari Edition. 4.6, locking CDL, and Detroits.
1994 LR RRC LWB. EAS conversion w/ +2" springs.
1968 LR SIIA 88" Hybrid, with 109" 1 ton axles SOA. Needs Tartis for completion.

1979 LR SIII 5 door 109 SW, 11 seater. Sold, 09'.
1997 Disco I Bobtailed buggy conversion. Sold, 11'.

Offline ArmyRover

  • Hero Member
  • *****
  • Posts: 1462
    • Email
Diff question for series and RRC type people
« Reply #7 on: April 02, 2009, 04:34:29 PM »
33 but I already passed on them 175 for both pairs of gears shipped, I'm probably going to regret that later.  

Oh well I'll do a yota rear swap instead.
Logged
"I disapprove of what you say, but I will defend to the death your right to say it."  ~Voltaire

Offline CliftonRover

  • Sr. Member
  • ****
  • Posts: 318
    • Email
Diff question for series and RRC type people
« Reply #8 on: April 02, 2009, 05:24:26 PM »
as far as gear strength goes I ran series diffs in my classic and they worked fine until I dropped a spider gear pin and blew the spider gears out the covers of each axle.  the ring and pinion didn't break though.  if you came across another pair it would not be a bad idea.  you could likely get a series diffs nd pull the gears out of them for a low price.
Logged

Offline Daniel

  • Hero Member
  • *****
  • Posts: 1280
    • http://www.x-trememarine.com
    • Email
Diff question for series and RRC type people
« Reply #9 on: April 02, 2009, 05:39:57 PM »
True. I can buy series diffs all day long for 50.00 a piece. Hell, I've got two or three right now just laying around that I don't need.
Logged
2002 LR DII SE Kalahari Edition. 4.6, locking CDL, and Detroits.
1994 LR RRC LWB. EAS conversion w/ +2" springs.
1968 LR SIIA 88" Hybrid, with 109" 1 ton axles SOA. Needs Tartis for completion.

1979 LR SIII 5 door 109 SW, 11 seater. Sold, 09'.
1997 Disco I Bobtailed buggy conversion. Sold, 11'.

Offline junkyddog11

  • Hero Member
  • *****
  • Posts: 539
    • Email
Diff question for series and RRC type people
« Reply #10 on: April 12, 2009, 09:42:45 AM »
I've got a whole fawkin truck full of series gears.
They really are not worth trying to run in a RRC. Unless you like changing them. They WILL break. They were not designed for the load of a 5000lb range rover. Thats why even series rigs break them fairly easily and the gears were redesigned for the coilers, which still aren't that rugged.

Don't regret it. Save your $$ for something worthwhile. 4:75 gears are a little low for 33"s anyhow unless you like driving at 3000 rpms. 4:11's are lower than stock it takes 35"s to get to stock gearing with them (4:11's).
« Last Edit: April 12, 2009, 09:50:29 AM by junkyddog11 »
Logged
Matt Browne
Oil Soaked Filter
http://www.overlandengineering.com .......one of those "other shops"

Offline ArmyRover

  • Hero Member
  • *****
  • Posts: 1462
    • Email
Diff question for series and RRC type people
« Reply #11 on: April 12, 2009, 02:48:02 PM »
I'm not banging my head against the wall to hard...

I found a yota e-locker rear diff for $35 complete yesterday with 4.11 gears.  Saving up now so I can give Kieth at rovertracks a call to order the other parts for the conversion :D and of course a TT and 4.11 for the front.
Logged
"I disapprove of what you say, but I will defend to the death your right to say it."  ~Voltaire

Offline junkyddog11

  • Hero Member
  • *****
  • Posts: 539
    • Email
Diff question for series and RRC type people
« Reply #12 on: April 12, 2009, 08:01:39 PM »
If I was you and you I'd stuff an e-locker in the front also. I'm not a big fan of them (damn sticky electric things) but they are cheap. For what you will spend on gears and shafts / cv's for a Rover set-up you can get Keiths toy bits.
Logged
Matt Browne
Oil Soaked Filter
http://www.overlandengineering.com .......one of those "other shops"

Offline ArmyRover

  • Hero Member
  • *****
  • Posts: 1462
    • Email
Diff question for series and RRC type people
« Reply #13 on: April 12, 2009, 09:32:10 PM »
If I come up with another one for cheap Matt I will.  I understand that the HP yota front diff is harder to come by though.

I'm almost done rebuilding the whole front axle on mine now, I might actually have a front axle with no leaks now....

Just need to swap the entire assembly in and the RRC will be back on the road :D
Logged
"I disapprove of what you say, but I will defend to the death your right to say it."  ~Voltaire
Pages: [1]
« previous next »