4.75 & 4.11 Rover Gears - Pirate4x4.Com : 4x4 and Off-Road Forum
 
Pirate4x4.Com : 4x4 and Off-Road Forum  

Go Back   Pirate4x4.Com : 4x4 and Off-Road Forum > Brand Specific Tech > Land Rover
Notices

Reply
 
Share Thread Tools Display Modes
Old 12-06-2006, 09:30 PM   #1 (permalink)
Registered User
 
Join Date: Aug 2004
Member # 34849
Location: utah
Posts: 260
4.75 & 4.11 Rover Gears

Ok asking for advice now suckers

Any you guys run 4.75 before you upgraded to bigger and better things? Would you agree 10x41 4.11 are stronger than stock 3.54 13x46?

some options out there:
GBR 4.11 10x41
GBR 4.75 8x38
KAM 4.11 ?
KAM 4.75 ?
Stock Series 4.7 10x47
Stock 3.54 13x46

according to KAM's website the 4.75 is 50% stronger than a stock gear set. How can that be true?

GBR 8x38 claims that there is less teeth but they are thicker allowing for greater strength. how can less teeth be stronger than series 4.7 10x47. In real life this does seem to be the case.

Look, don't want to hear go toy, go sals, go dana blah blah. People who ran these only please. Thank you amigo's
krazz1e is offline   Reply With Quote Quick reply to this message
Old 12-06-2006, 09:42 PM   #2 (permalink)
Registered User
 
Buckon37s's Avatar
 
Join Date: Jun 2003
Member # 20394
Location: San Diego
Posts: 4,733
go toy, go sals, go dana
__________________
[I]BUCK[/I] Wild Racing
Team 911

Thank you all for your support

Widia Cutting Tools [url]www.widia.com[/url]
Sterling Autosport [url]www.sterlingautosport.com/[/url]
PSC [url]www.pscmotorsports.com/[/url]
Ruffstuff [url]www.ruffstuffspecialties.com[/url]
Tom Woods Drive Shafts [url]www.4xshaft.com[/url]
[url]www.facebook.com/buckwildracing[/url]
Buckon37s is offline   Reply With Quote Quick reply to this message
Sponsored Links
Old 12-06-2006, 09:53 PM   #3 (permalink)
Registered User
 
Join Date: Mar 2006
Member # 68649
Location: Australia
Posts: 1,404
Thicker teeth allow for a thicker more ductile core. but I would assume this would be offset a little by having less actual teeth in mesh. I ran English Ford Transit diffs in my Rover at one time, and their 5.6 :1ring and pinions were actually stronger than their 4.625:1 due to less but thicker teeth.
I would like to see some company design a ring and pinion that continues the length of the ring gear teeth all the way to the circumference ofthe carrier as Toyota did on their later Landcruiser diffs
Bill.
Agrover is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 01:42 AM   #4 (permalink)
Registered User
 
Join Date: Apr 2006
Member # 71212
Location: Oliveira do Arda - PORTUGAL
Posts: 30
Send a message via MSN to nunoeumiranda
I used the series and broke 2 in a half
I bought the KAM 4,75 and until now nothing to say.. running very well with my MAxxis 35".... never broke

But definitely GO TOY
nunoeumiranda is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 11:06 AM   #5 (permalink)
Rock God
 
Greg Davis's Avatar
 
Join Date: Apr 2002
Member # 11066
Location: Charlotte, NC
Posts: 1,260
I ran the 4.75's in my DII and lost some teeth off the ring gear on my first trip to Moab. From what we could tell, the pinion deflected enough to take off the ends of a few of the ring gear teeth. Ended my trip right there since GBR was out of stock at the time.
__________________
"Wrinkles Only Go Where The Smiles Have Been" - Jimmy Buffett
Greg Davis is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 11:58 AM   #6 (permalink)
Registered User
 
Join Date: Oct 2001
Member # 7755
Location: Main Line PA
Posts: 1,918
"Would you agree 10x41 4.11 are stronger than stock 3.54 13x46?"

NO!!!!!

Lower numerically is stronger. 4.11 blow up as do, especially the 4.75s. someone posted up about pinning the diffs, short of that you will break them.

Salisbury rear, toy front or Eaton Rear/D60 front.
__________________
:evil:
evilfij is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 12:08 PM   #7 (permalink)
I build stuff
 
aloharover's Avatar
 
Join Date: Oct 2002
Member # 14561
Location: Just outside the evac zone
Posts: 16,768
Quote:
Originally Posted by evilfij
Salisbury rear, toy front or Eaton Rear/D60 front.


Call dynatrac and just have them make D60 f&r for you. Change to a more common (ie. cheeper to get rims) bolt pattern.
__________________

Want to know how I lost 45lbs? Try INSANITYŽ.
www.beachbodycoach.com/petermhope

"I wake up in the morning and piss excellence"

Colorado Springs, CO Based FFL-07/SOT
aloharover is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 12:15 PM   #8 (permalink)
Registered User
 
Join Date: Oct 2001
Member # 7755
Location: Main Line PA
Posts: 1,918
Salisbury rear, toy conversion front keeps the rover bolt pattern.

Eaton rear, D60 front is 8 lug.

You have have gold plated daytona 144 spoke 20s for the cost of a pair of dynatrac 60s as opposed to $1500 for either of the above combos.
__________________
:evil:
evilfij is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 12:22 PM   #9 (permalink)
I build stuff
 
aloharover's Avatar
 
Join Date: Oct 2002
Member # 14561
Location: Just outside the evac zone
Posts: 16,768
Quote:
Originally Posted by evilfij
Salisbury rear, toy conversion front keeps the rover bolt pattern.

Eaton rear, D60 front is 8 lug.

You have have gold plated daytona 144 spoke 20s for the cost of a pair of dynatrac 60s as opposed to $1500 for either of the above combos.
So you are saying you can find a Salisbury here in the US and do the toy conversion for 1500$?
__________________

Want to know how I lost 45lbs? Try INSANITYŽ.
www.beachbodycoach.com/petermhope

"I wake up in the morning and piss excellence"

Colorado Springs, CO Based FFL-07/SOT
aloharover is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 01:07 PM   #10 (permalink)
Registered User
 
Join Date: Oct 2001
Member # 7755
Location: Main Line PA
Posts: 1,918
I am cheap. Maybe you end up at around 2k-2500 after lockers.

My salisbury was $250 or so. ECR blows them out every year at that price or less for the drum take offs (last year it was $150). $325 for the Detroit and $400 for shafts.

Pick and pull the toy diff for $50.

What does keith get for the toy axles? I know the rover ones he sells are $660.

Ron
__________________
:evil:
evilfij is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 01:42 PM   #11 (permalink)
I build stuff
 
aloharover's Avatar
 
Join Date: Oct 2002
Member # 14561
Location: Just outside the evac zone
Posts: 16,768
Quote:
Originally Posted by evilfij
My salisbury was $250 or so. ECR blows them out every year at that price or less for the drum take offs (last year it was $150). $325 for the Detroit and $400 for shafts.
What are they swapping out the Salisbury for?
I had never seen a RTR complete drum to drum rear go for less the 700$ before.
__________________

Want to know how I lost 45lbs? Try INSANITYŽ.
www.beachbodycoach.com/petermhope

"I wake up in the morning and piss excellence"

Colorado Springs, CO Based FFL-07/SOT
aloharover is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 01:54 PM   #12 (permalink)
Registered User
 
Join Date: Oct 2001
Member # 7755
Location: Main Line PA
Posts: 1,918
ECR swaps out all the drum brake 110 rears for complete 110 salisbury disc axles. They sold two or three last year but I was too busy to drive up (they also had a take off 110 SW tub which is what I really wanted, but it sold before I had a chance to get up there).

I bought mine out of Ohio for $250 or $300 IIRC four years ago, and it had the sway bar mounts on it.
__________________
:evil:
evilfij is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 03:56 PM   #13 (permalink)
Registered User
 
Join Date: Aug 2004
Member # 34849
Location: utah
Posts: 260
$300 for a sals? sign me up.

ok some good info folks.

So shifting gears now, Toy Front gives 30 spline and more options on gearing. I've seen a toy R&P and they don't seem much beefier, so why are they stronger?
krazz1e is offline   Reply With Quote Quick reply to this message
Old 12-07-2006, 05:00 PM   #14 (permalink)
Registered User
 
Join Date: Oct 2004
Member # 36981
Posts: 2
It's the fundamental design of the diff!

toy=hypoid: pinion intersects the ring off set towards the top or bottom of the ring
rover=shit i.e. spiral bevel: pinion intersects the ring at the center

Yeah, there are some stout spiral bevel 3rds i.e. ENVs, but the larger larger tooth engagement area for a hypoid style diff is stronger than rover shit, given the same ring diameter, R&P ratio...
grnrvrs is offline   Reply With Quote Quick reply to this message
Old 12-08-2006, 12:51 AM   #15 (permalink)
Registered User
 
Join Date: May 2004
Member # 30584
Posts: 186
Quote:
Originally Posted by krazz1e
Ok asking for advice now suckers

Any you guys run 4.75 before you upgraded to bigger and better things? Would you agree 10x41 4.11 are stronger than stock 3.54 13x46?

some options out there:
GBR 4.11 10x41
GBR 4.75 8x38
KAM 4.11 ?
KAM 4.75 ?
Stock Series 4.7 10x47
Stock 3.54 13x46

according to KAM's website the 4.75 is 50% stronger than a stock gear set. How can that be true?

GBR 8x38 claims that there is less teeth but they are thicker allowing for greater strength. how can less teeth be stronger than series 4.7 10x47. In real life this does seem to be the case.

Look, don't want to hear go toy, go sals, go dana blah blah. People who ran these only please. Thank you amigo's
Hi,

we make and sell a heck of a lot of 4.11 R & P gears, ours use a 9/37 tooth count and we have very few problems with them, I have seen a couple of failures but usually only when the pinion bearings collapse or the driver owns up to jumping the front axle 5 foot in the air,

as a rule the lower the ratio the weaker the R & P gear assuming all other things are equal, as the ratio gets lower the pinion gets smaller diameter, so you are transmitting the same load through less teeth,

To answer your original question, despite the above theory I don't think there is a great deal of difference between the 3.54 and the 4.11, I have seen more broken 3.54's but this may be because :

1) there are more out there

2) often they fail because they are on the stock 2 pin diff centre that just flexes and lets the R & P get out of mesh,

although some people like the 4.75 ratio, I am not a great fan of them because of a few reasons :

the pinion diameter is too small and asking for trouble,

for most people they are too low and not ideal on the road (I guess this depends on tyre size),

very slow seller, the last batch of 50 we made too 2 years to sell, we sell over 300 4.11's a year,
__________________
regards

Dave

www.ashcroft-transmissions.co.uk
ashtrans is offline   Reply With Quote Quick reply to this message
Old 12-08-2006, 01:52 PM   #16 (permalink)
Registered User
 
Join Date: Aug 2004
Member # 34849
Location: utah
Posts: 260
so i think GBR gears are KAM gears.

nevertheless, I may be forced to go something else due to the lack of options and strength here.

I have a set of 4.75 special reverse cut gears for the front, I just need to find something strong for the rear... doesn't look like that will happen. Does anyone have some 4.75's laying around from swaps? Not thrilled to spend $500 for GBR when I know they will break.
krazz1e is offline   Reply With Quote Quick reply to this message
Old 12-08-2006, 02:14 PM   #17 (permalink)
Registered User
 
Buckon37s's Avatar
 
Join Date: Jun 2003
Member # 20394
Location: San Diego
Posts: 4,733
Quote:
Originally Posted by krazz1e
so i think GBR gears are KAM gears.

nevertheless, I may be forced to go something else due to the lack of options and strength here.

I have a set of 4.75 special reverse cut gears for the front, I just need to find something strong for the rear... doesn't look like that will happen. Does anyone have some 4.75's laying around from swaps? Not thrilled to spend $500 for GBR when I know they will break.
Don't worry, your front will break too.
__________________
[I]BUCK[/I] Wild Racing
Team 911

Thank you all for your support

Widia Cutting Tools [url]www.widia.com[/url]
Sterling Autosport [url]www.sterlingautosport.com/[/url]
PSC [url]www.pscmotorsports.com/[/url]
Ruffstuff [url]www.ruffstuffspecialties.com[/url]
Tom Woods Drive Shafts [url]www.4xshaft.com[/url]
[url]www.facebook.com/buckwildracing[/url]
Buckon37s is offline   Reply With Quote Quick reply to this message
Old 12-09-2006, 10:30 AM   #18 (permalink)
Registered User
 
Join Date: Dec 2002
Member # 15710
Location: I forgot...
Posts: 1,265
Actually Yousef ran 4.75 GBR gears up front for a couple of years in his 90... He broke a lot of stuf but not those gears...
I'm not sure about the difference in ratio diff but what about 4.88 toy in the rear and 4.7 up front? it's only about 2.5%... I've never actually thought about it much..
__________________
Keith
[url]www.rovertracks.com[/url]
[FONT="Arial Black"][I][COLOR="Red"]"in this case your best best is to put in first, floor it and hold on"[/COLOR][/I][/FONT]
revor is offline   Reply With Quote Quick reply to this message
Old 12-09-2006, 08:57 PM   #19 (permalink)
Registered User
 
Join Date: Jan 2002
Member # 9615
Location: Calgary
Posts: 95
You guys all need to get 2.5na diesels in your rovers... you'll never brake anything that way
western110 is offline   Reply With Quote Quick reply to this message
Old 12-10-2006, 03:12 PM   #20 (permalink)
Registered User
 
Join Date: Mar 2006
Member # 69597
Location: Clinton ut
Posts: 1,438
Quote:
Originally Posted by ashtrans
Hi,

we make and sell a heck of a lot of 4.11 R & P gears, ours use a 9/37 tooth count and we have very few problems with them, I have seen a couple of failures but usually only when the pinion bearings collapse or the driver owns up to jumping the front axle 5 foot in the air,

as a rule the lower the ratio the weaker the R & P gear assuming all other things are equal, as the ratio gets lower the pinion gets smaller diameter, so you are transmitting the same load through less teeth,

To answer your original question, despite the above theory I don't think there is a great deal of difference between the 3.54 and the 4.11, I have seen more broken 3.54's but this may be because :

1) there are more out there

2) often they fail because they are on the stock 2 pin diff centre that just flexes and lets the R & P get out of mesh,

although some people like the 4.75 ratio, I am not a great fan of them because of a few reasons :

the pinion diameter is too small and asking for trouble,

for most people they are too low and not ideal on the road (I guess this depends on tyre size),

very slow seller, the last batch of 50 we made too 2 years to sell, we sell over 300 4.11's a year,
are yours reverse cut?
mightymg1 is offline   Reply With Quote Quick reply to this message
Old 12-10-2006, 08:47 PM   #21 (permalink)
Registered User
 
Join Date: Aug 2004
Member # 34849
Location: utah
Posts: 260
Quote:
Originally Posted by revor
Actually Yousef ran 4.75 GBR gears up front for a couple of years in his 90... He broke a lot of stuf but not those gears...
I'm not sure about the difference in ratio diff but what about 4.88 toy in the rear and 4.7 up front? it's only about 2.5%... I've never actually thought about it much..
hmm perhaps, i'll look into this. but then again, the toy gears aren't that much beefier than rovers, though there are much more options and they are cheaper.
krazz1e is offline   Reply With Quote Quick reply to this message
Old 12-10-2006, 08:49 PM   #22 (permalink)
Registered User
 
Join Date: Aug 2004
Member # 34849
Location: utah
Posts: 260
Quote:
Originally Posted by mightymg1
are yours reverse cut?
no, ashcrofts are not.

Which brings me to my next question, how much stronger does the reverse cut make it?

I am 90% sure KAM & GBR are reverse cut (or were at one point).
krazz1e is offline   Reply With Quote Quick reply to this message
Old 12-11-2006, 12:44 AM   #23 (permalink)
Registered User
 
Join Date: Feb 2003
Member # 17316
Location: WA
Posts: 1,319
Quote:
Originally Posted by krazz1e
no, ashcrofts are not.

Which brings me to my next question, how much stronger does the reverse cut make it?

I am 90% sure KAM & GBR are reverse cut (or were at one point).
Reverse cut gears should be used on the front only AFAIK - means they will be as strong as a rear when driving forwards. There is another option for a 4.7:1 diff - still a 10/47 ratio, but a very strong coiller only version made for the front diff of the Australian Army perentie 6x6s - it costs about $900 for one ring and pinion though (and yes it is reverse cut).
__________________
Cheers,

Ben.

Last edited by ISUZUROVER; 12-11-2006 at 12:45 AM.
ISUZUROVER is offline   Reply With Quote Quick reply to this message
Old 12-11-2006, 05:15 AM   #24 (permalink)
Granite Guru
 
Junkyddog11's Avatar
 
Join Date: Nov 2005
Member # 59532
Location: Maine
Posts: 505
Quote:
Originally Posted by western110
You guys all need to get 2.5na diesels in your rovers... you'll never brake anything that way
hmmmn...the only thing I can't break with the 2.5na is the fawkin' speed limit......
__________________

Matt Browne
Dedicated to the resurrection of junk through engineering?
'61 88" IIA 2.5na "Soiled"
'89 RRC 300 Tdi 5spd "Swampslut"
'95 RRC LWB 300 Tdi auto
www.overlandengineering.com.....expansion complete. Now, the only Rover shop in Eliot Maine....is also the biggest.
Junkyddog11 is offline   Reply With Quote Quick reply to this message
Old 12-11-2006, 06:09 AM   #25 (permalink)
Registered User
 
Join Date: Jun 2002
Member # 12499
Location: In a Snap-On truck tryin' to make it pay
Posts: 10,926
Quote:
Originally Posted by Junkyddog11
hmmmn...the only thing I can't break with the 2.5na is the fawkin' speed limit......
LOL, the only thing I seem to break with my Rover is shock absorbers (and tires)
PTSchram is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Pirate4x4.Com : 4x4 and Off-Road Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.

** A VERIFICATION EMAIL IS SENT TO THIS ADDRESS TO COMPLETE REGISTRATION!! **

Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 11:53 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0 ©2011, Crawlability, Inc.