Alberta Land Rover Enthusiasts Club Forum
General => Technical Discussions => Topic started by: JohnnyO on February 21, 2026, 09:24 AM
I am considering replacing the front differential on the 1994 NAS D90. It has 320K kms and slack in the drive train. I have already replaced the transmission and transfer case so the diffs are next. Let's be clear, I hired someone for the tranny and t-case. This time it's going to be the Land Rover turning the owner into a mechanic! I am open to any thoughts, expertise, encouragement and wrenching assistance. So here goes, wish me well...
My research has shown this is 3.54:1, 4 Spline, 4 Bolt Flange. Does that sound right??
I am thinking about ordering a rebuilt diff. Thoughts??
Rovers North (https://www.roversnorth.com/parts/ftc3272a_rebuilt_differential_assembly_3_54_1_2_pin_24_spline_4_bolt_flange)
Ashcroft (https://ashcroft-transmissions.co.uk/product/rover-type-diffs/)
Is the replacement really this straightforward??
It makes sense to get a better diff, as it will be stronger and have less backlash. Ashcroft 4 pin or ATB or a used stock 4 pin, if you can find one.
Then the last thing to consider is the half shafts, CVs and drive flanges. They may have wear as well. But you could always go back. It is easier the second time.
Happy to come around and offer support.
As to the work, you can do it the way in the video, pulling the entire assemblies or by pulling the hubs and spindles. I usually do the latter as you can replace the hub seal, check the CV out and adjust the hub bearings. Just make sure you have the right seals, gaskets and washers on hand.
Happy to help out.
Thanks John.
I'm okay doing this in stages, there's no rush. What should I be looking to tackle first? If the easiest and/or highest value areas can be identified, we can start there. Once that's in place, move on to the next bits, and so on.
Well. You might as well do the diff first. It is the most likely cause of the backlash. Am I right that you already did the drive flanges? Those are a common location for wear.
Oh yeah, I forgot about the drive flanges. I'll start there.
Are the HD Ashcroft ones the best bet? P/N 859 (Land Rover part number FTC859 which supercedes to RUC105200)
https://ashcroft-transmissions.co.uk/product/859/ (https://ashcroft-transmissions.co.uk/product/859/)
Will these work with the NAS alloy wheels?
Are the flanges the same front and read? I'm thinking I might as well do all four corners.
Yes. Those are the right ones and a good choice.
The rear axles would not have flanges if they are original. They should have one piece halfshafts with integral flanges.
Confirmed, rears are one piece
(https://uploads.tapatalk-cdn.com/20260222/b1c89f7c3b1d826f1f31b70823781fe7.jpg)
Sent from my iPhone using Tapatalk
Pulled apart the front to take a look...
Sent from my iPhone using Tapatalk
(https://uploads.tapatalk-cdn.com/20260222/e1d15f0979c7277e1610de9a61281af8.jpg)
Sent from my iPhone using Tapatalk
(https://uploads.tapatalk-cdn.com/20260222/ab4fa4441f914f968671311e362cddec.jpg)
Sent from my iPhone using Tapatalk
Slide the drive flanges back on. Be careful not to push the CVs in as they can fall off the spindles.
Rotate them back and forth and see how much free play there is between the two parts. When new, there should be no play.
Hmm OK, so now I'm up against a bit of of a challenge. It's looking like a 52
mm socket to get the hub nut off. I'm seeing these on the Landy sites but does anyone know of a local Calgary supplier?
(https://uploads.tapatalk-cdn.com/20260222/a70ac1828f443fef6e79006edc7abad2.jpg)
Sent from my iPhone using Tapatalk
With the drive flanges back on there isn't a whole lot of free play - some but not much. I suspect new ones will be tight but I'm going to say this not the majority of the slack.
Britpart DA1118
https://www.lrdirect.com/da1118-1-2-inch-drive-52mm-deep-socke
Quote from: JohnnyO on February 22, 2026, 05:06 PMWith the drive flanges back on there isn't a whole lot of free play - some but not much. I suspect new ones will be tight but I'm going to say this not the majority of the slack.
It's funny u should ask.... I have a new one here still sitting in the bag😉
Sorry Bill, are you saying you have drive flanges available?
Sent from my iPhone using Tapatalk
Is this the correct front diff for a 1994 NAS 90? I plan to go for the ATB.
https://ashcroft-transmissions.co.uk/product/rover-type-diffs/
(https://uploads.tapatalk-cdn.com/20260227/83a61fef8e75dbc9caf88ad64bc83a96.jpg)
Sent from my iPhone using Tapatalk
For ordering, is my only option to order directly from Ashcroft?
(https://uploads.tapatalk-cdn.com/20260227/6f87e55fe27d463ed7946633b0e0b2ef.jpg)
Sent from my iPhone using Tapatalk
Yes. That is the right one. I'm pretty sure ordering direct is the lowest cost option.
I was referring to the 52mm socket for removing the wheel bearing nuts 😁LR part # 606435
Definitely order direct. If you have any questions call and ask for Dave , and he will answer all your questions and more.
Sent you a PM.
Thx James
I have a gently used rebuilt Ashcroft diff on its way from Edmonton. (Thanks James!). What is the RTV sealant mentioned in the video? (Caulking in the screen shot below.) Are there gaskets? When bolting things back together, where do I need thread locker and where do I need anti seize? What else should I be thinking of?!
(https://uploads.tapatalk-cdn.com/20260302/46715f6c9a65818567237998001e92d7.jpg)
Sent from my iPhone using Tapatalk
The factory method is a gasket. Some people prefer sealant. There are pros and cons.
Thread locker needed locations are in the manual. Swivel to axle housing bolts and caliper mount bolts are the main ones. Note both have 12 point heads. Drive flange bolts are a good idea, as well, as the narrow drive flanges like to come loose.
My suggestion is to read the manual and avoid youtube...
Roger that. Good advice. My Workshop Manual is 1996-1998 (came with the old 110). Flipping through it things look recognizable enough to be used for a 1994 NAS.
(https://uploads.tapatalk-cdn.com/20260303/cd65581112c662a1ed83e7ae320f8dfd.jpg)
Sent from my iPhone using Tapatalk