Snagger Posted December 9, 2022 Share Posted December 9, 2022 Hi all. Can anyone please provide the dimensions of the offset from the back (smooth) side of the ring gear to the pinion axis for both 4.71 and 3.54 gear sets? I’m trying to determine if the 4.1 Dana gears will need a spacer ring on a 110 spec diff centre (the 4.71 obviously would). Thanks. Quote Link to comment Share on other sites More sharing options...
Snagger Posted December 11, 2022 Author Share Posted December 11, 2022 Gazzar mentioned in his 101 thread a discussion on AULRO about Dana 60s into 101s that had the following screen shot comment, so it appears that my 4.1 gear set should fit the Defender spec Ashcroft ATB, but that the 4.71 SIII gear set would need a spacer. Again, if anyone knows the diff flange offset difference (and thus spacer ring thickness) please sing out. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 11, 2022 Share Posted December 11, 2022 Ashcroft sell a spacer ring to allow you to fit 4.7s to 3.54 Rover centre, so perhaps it is the same difference? I'd assume they would know if asked. Quote Link to comment Share on other sites More sharing options...
Snagger Posted December 11, 2022 Author Share Posted December 11, 2022 I enquired about a spacer ring but got no reply from them (or Nige). I haven’t found anything on a Google search either. I’d be very surprised indeed if the Rover and Salisbury offset variations for the different ratios were comparable. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted December 11, 2022 Share Posted December 11, 2022 If you can wait until I'm at the stage of doing my axles I'll get the series 3 measurement. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted December 12, 2022 Author Share Posted December 12, 2022 Thanks Gary. The ring gear will be thicker than the pinion head smaller than a 109’s but the pinion axis to smooth face of the ring gear should be the same. I presume you are leaving the pinion in place, so measuring that offset would be tricky. If you could stand the stripped diff on one of its bearing seat ends and measure the height to the mating face of the flange, I can compare that to the same measurement on my ATB. That should be accurate enough for me to get a spacer ring made up and fine tune with shims. Much appreciated Quote Link to comment Share on other sites More sharing options...
Snagger Posted December 14, 2022 Author Share Posted December 14, 2022 I took these measurements off the Dana 4.1 gear set. It’d be very useful if someone has the Salisbury dimensions. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 13, 2023 Share Posted January 13, 2023 Is this of any benefit? https://www.differentials.com/technical-help-2/carrier-breaks/ G. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 14, 2023 Author Share Posted January 14, 2023 Yes, but conflicts with other information. That AULRO post in the other thread has the gear spec split at 4.3 and lower and 4.56 and higher, not 4.1 vs 4.56. The deck height here varies by 0.195”, but the Dana60 spacer ring in the advert I screen shot was specified as 0.155-0.165”. It is concerning to see so many contradictions, though I don’t think that spacer ring appeared to be of great quality (the thickness variation suggests that all by itself) and I did say it seemed thinner than I expected. Easy enough for a gear ratio to have been missed from the table in your link above, I suppose, especially if it is an uncommon ratio. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 14, 2023 Share Posted January 14, 2023 What we don't know is exactly how similar the Dana made and the Landrover made carriers are. Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 15, 2023 Author Share Posted January 15, 2023 There seem to be numerous types for the Dana, some like the Salisbury, some like a large Rover diff with single pin and open centre, and probably many more. The Dana specs seem more about the pinion and ring gear and the casing dimensions than the diff itself. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 15, 2023 Share Posted January 15, 2023 @Snagger I've an aftermarket CW&P for a salisbury, 4.7. Do you need dimensions from that? G. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 16, 2023 Author Share Posted January 16, 2023 14 hours ago, Gazzar said: @Snagger I've an aftermarket CW&P for a salisbury, 4.7. Do you need dimensions from that? G. The diff flange to pinion axis measurement would be very useful. Is your gearset for a 110 diff or 109? Being aftermarket, I have a suspicion it might be the latter for Defenders fitted with oversize tyres. If you know whether it was meant to replace the 4.71 gears on the 109 or the 3.54 on a 110, let me know, because it obviously would differ for that flange position. Either way, the measurement will be useful for me to know the spacer thickness if it’s a 109 gear or to confirm my 4.1 gears will fit if it’s for a 110. Regardless, if you could post up the pinion measurements as I did for the Dana gears, that’d be an enormous help for me to know if the pinion will fit the Salisbury spec bearings (I read conflicting information that one of the inner races may be a different size) and whether the LR flange will fit the splines (I have a seemingly rare 10 spline Dana set). Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 16, 2023 Author Share Posted January 16, 2023 On 1/14/2023 at 8:57 AM, Snagger said: Yes, but conflicts with other information. That AULRO post in the other thread has the gear spec split at 4.3 and lower and 4.56 and higher, not 4.1 vs 4.56. The deck height here varies by 0.195”, but the Dana60 spacer ring in the advert I screen shot was specified as 0.155-0.165”. It is concerning to see so many contradictions, though I don’t think that spacer ring appeared to be of great quality (the thickness variation suggests that all by itself) and I did say it seemed thinner than I expected. Easy enough for a gear ratio to have been missed from the table in your link above, I suppose, especially if it is an uncommon ratio. Incidentally, as I mentioned on the other thread, it appears a thinner spacer is better in the case of the Ashcroft ATB as it hides less of the locating centre for the ring gear - the thicker spacer takes about 1mm more of that away, leaving just under 2mm to hold the ring gear centred. The more of that thickness that can be made up by shimming the bearings to move the entire diff into mesh with the pinion, the better. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 16, 2023 Share Posted January 16, 2023 It was advertised as 109 fitment. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 16, 2023 Share Posted January 16, 2023 I'm not sure if the StationMaster will give clearance for me to go to the workshop tonight, but she might; I'll do as soon as I can. Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 16, 2023 Author Share Posted January 16, 2023 No rush. The pinion dimensions, other than gear diameter and tooth count, should be the same regardless, so those measurements would be extremely useful to compare to mine. With it being for 109, the offset is useful for that spacer thickness outdoor I end up retaining the 109 gears. Thanks, Gary. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 16, 2023 Share Posted January 16, 2023 How would I measure offset? Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 16, 2023 Share Posted January 16, 2023 How would I measure offset? Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 16, 2023 Author Share Posted January 16, 2023 It’s very rough, but I laid the ring gear on the bench, sat the pinion into it in the middle of the thrust range that it seemed a comfortable fit (you will feel how “off” it is if you push the head too far toward or away from the ring gear centre, and will have a comfortable range of only 1-2mm), and then measured from bench to pinion head centre. A measurement to the nearest half mm is a good guideline for what we are working out at this point. It’s the measurement on the far right of my sketch (62.29mm, 2.452” as best I could manage with this iffy method 😉) . 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 16, 2023 Author Share Posted January 16, 2023 By the photos, it looks like the Salisbury has a larger internal diameter on the bearing nearest the prop flange. Flange splines may be similar, but only measurements will tell. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 16, 2023 Share Posted January 16, 2023 I confess I thought you had a whizzy scientific way of measuring offset rather than what you suggested. I know what you mean regarding where the pinion fits nicely. Will do what I can. 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 16, 2023 Author Share Posted January 16, 2023 59 minutes ago, Gazzar said: I confess I thought you had a whizzy scientific way 😂😂 No such luck! I have to resort to the simple and practical. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 16, 2023 Share Posted January 16, 2023 In that spirit, first go. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted January 16, 2023 Share Posted January 16, 2023 And. Quote Link to comment Share on other sites More sharing options...
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