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uninformed

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Everything posted by uninformed

  1. I’m hoping so, and a little “chissssh chisssh” touch up here and there
  2. It’s my understanding that even zinc electro plating can cause it. To a lesser extent, but I did discuss it with a knowledgeable friend. I imagine at the least, dipping in the hydrochloric acid a part of that. These studs are Class 10.9, so not quite the top, but still considered high tensile.
  3. Some thoughts… regarding the CW bolts for using a Dana 60 gear set in a Salisbury. Double check the length required and what you are buying. Factor in spacers if required and depending on bolt type if a washer is required. Looking at the ARP ring gear (Crown wheel in our world) bolts, they don’t use a washer. This is fine, especially with the larger head area. Do take a good look at the underside of any bolt to see how much of a radius it has transitioning from under side of head to shank. Most standard ARP bolts have a generous radius and are supplied with a chamfered washer to allow clearance for it (you don’t want that radius binding on or in). If not using washers you can use a chamfer or deburring bit to put a relief in your hemisphere holes. ALWAYS use hardened washers. Anything soft will deform, not only during installation, but also in use, reducing bolt preload and resulting in failure. Most lock washers are useless,ESPECIALLY split washers. They belong in the bin. If you feel the need, use something good, again hardend, like Nord-Lock If buying a bolt with a smooth shank MAKE SURE the transition from shank to thread is not right near the mounting face of crown wheel. As there is no counterbore in the threaded hole, the transition should be at least 1.5 full threads inside the hemisphere. Reason being is the shank to thread is a stressed area, as is the mounting face of crown wheel, you don’t want these meeting together.
  4. If you want to go high quality like ARP, trust their knowledge and judgement by using what they design for the job. Take note of the head type on their Ring Gear and Fly Wheel bolts. There is reason to this design and the fact it’s not the standard ARP bolt head or stud nut should tell you something.
  5. If you are thinking that a stud needs to bottom out in a blind hole, that is incorrect and not good practice
  6. Good to hear 👍👍 The advantage of the American stuff is volume and availability… a quick google had bolts coming from everywhere lol. Even though a couple places called them Grade 8, I highly doubt they are given the head markings, which are consistent with Grade 9 ( these have a UTS of 180,000 Psi , same as Class 12.9 ) You have plenty of options… https://shop.broncograveyard.com/mobile/D60-Ring-Gear-Bolt-Set-12/productinfo/11847/ https://www.strangeengineering.net/product/dana-60-ring-gear-bolts-with-washers-set.html/ screenshot:
  7. The bolt/joint is not designed to be in shear. It is the clamping force and surface friction that is important. Yes plenty of bolts shear but that’s the symptom not the cause… The shoulder on the hemisphere should be an interference fit with the crown wheel. You’ll find the holes in the hemisphere are not on size for shear (they have clearance). You will probably find they do NOT have enough clearance for 1/2” UNF bolts. Plenty drill them out for Dana gear sets. If all threads, bolts etc are good , true and installed correctly, AND you spin or loosen, you have gone beyond the design limits. Placing the bolt in shear is not always the answer, even when designed, as can be noted with Toyota Land Cruiser drive flange stud failure… You won’t buy a 1/2” bolt in 8.8,10.9 etc, that is the Metric Class system of rating. You will buy grade 8, or even Grade 9 (equivalent of Class 12.9). Though the SAE has not officially recognised Grade 9, there are some good brands and some carp… You could go to the ARP catalogue and see what they have for Dana 60 (try part number 200-3001, they are 1.060” UHL ) If you can get genuine factory Dana bolts, they will be good quality. I see absolutely no problem using bolts in the 180,000 UTS strength range as the vast majority of OEM do and it’s the minimum in Motorsport. Make sure you install the bolts to the torque specification of the bolt, especially if you are changing the strength of the bolt, ie don’t just go by the WSM. Edit: I will add if your genuine LR bolts are marked as 10.9 and you want to stay with that, Grade 8 is the equivalent (Please don’t confuse Class 8.8 for Grade 8, not that you’ll buy a 1/2” bolt in Class 8.8) A note on D60 gear sets, it has been proven that very few to none of the aftermarket brands are as good as genuine Dana.
  8. The Whitworth thread form is actually VERY good, better in fact than SAE UNC/UNF and Metric, simply because he got it right by using a true radius at thread root and tips. The others use a flat and this creates a larger stress riser. The same reason SAE developed UNR for aerospace etc Be that as it may, the availability of good bolts is non existent. The fact they suggested using a LR swivel bolt shows that even back then. While LR bolts (Atlas) are generally good quality , the standard for Whitworth bolts ment the highest strength available was between SAE Grade 5 and Grade 8. As an example, most factory Crown wheel bolts across the brands would be at LEAST Grade 8, and plenty are higher being the equivalent of Class 12.9 Shock loading is high in the application of a crown wheel, much like that of a flywheel to crank. You might notice the original crown wheel bolts LR used had a ‘funny’ head. This was done for a reason, it’s old but very good tech. The head acts like a shock absorber to a degree. Google ‘Place Bolt’ This head type has been and is still used in high shock applications. In vehicles, Ive seen them factory fitted to crown wheels, fly wheels and drive flanges.
  9. I have not had my hands in a Series Salisbury, but a quick google revealed the bolt part number of RTC773, and this is stated to be M12….
  10. Any idea of the installation torque LR specifies? I only have WSM up to 98 for Def’r, the D2 WSM I looked at did not have the spec, and by this stage were saying to send the diff back to LR or replace it…
  11. That would be a very strange choice for Kam to make and one would question their thinking if that the case… Rover CW have been 3/8 UNF since at least Series 2 and didn’t change . Not sure about the short nose/P38 type (assume the same) Ironically LRs supplier of Salisbury took an American diff and made the crown wheel metric thread 😆
  12. I’m looking for a ratio 3.75 - 3.9 , Rover diffs front and rear, 110 with M57, ZF 6 speed manual LT230 (30% reduction gears) It will probably weigh in around 2300kg Definitely not a comp rig, touring and some weekend off roading etc. diffs won’t be pegged. I wasn’t aware of Britpart doing alternative ratios? And am looking for something stronger than genuine. Ashcroft use to be made in Spain (no idea now) , but no idea where Kam or GBR are made?
  13. I won’t be pegging my cases at this stage. So who has any recent experience with Kam/Terrafirma CW&Ps?
  14. The one thing I can comment on going by photos as I have not had all 3 in hand, is the base material thickness below the root of CW teeth is thinnest on the Ashcroft. I guess it’s a combination of tooth size and pressure angle. Ashcroft use a 8 tooth pinion, GBR and Kam both use a 10 tooth pinion for their 3.9 and 3.8 respectively.
  15. At some point TerraFirma bought out Kam. I have found 3.8-1 which would suit but there seems little stockists. I’d also like to know where they are manufactured. Spain and Italy have somewhat ok reputation for CW&Ps, China not so much…
  16. Hey all, are there any other suppliers of heavy duty CW&Ps for Rover diffs other than Ashcroft and Great Basin Rovers? Personally I’m looking for something in the 3.75 to 3.9 ratio region cheers 🍺
  17. I’ll have to do something. At worst I have some zinc rich black spray paint (that would require periodic touch ups) I wasn’t keen on sending away for zinc plating for risk of hydrogen embrittlement. maybe I could do one of those DIY chemical electro set ups. (More bloody research 🤦🏻‍♂️😁) I’ve already pressed half of them in, but they do stick out beyond the drive flange mounting surface so it’s still possible to place the hubs studs down in a solution and the first 5mm will get done at least… I know the UK is worse for rust in ways, but it’s a pain here. The rear of chassis is a mess and I just had to grab my front calipers out of a storage tub due to them starting to head south badly… my kingdom for a real shed lol…
  18. all I’ll say is read this thread…
  19. Less rotational and unsprung mass of course…… 😆
  20. There are lots of tools/machinery you have that I’d love 🥰
  21. The problem I found when diving into the world of studs and ordering them, was part numbers did not guarantee length and or head design. I bought small packs of various and even 30 when thinking on the right track (going by the absolute reassurance of others) , then the end result was where I’m at 🤷🏻‍♂️
  22. Good shaft design dictates the dia should be no bigger than the root dia of the spline. So if you are replacing shafts with the same spline type and one is thicker, it may just mean that it’s less able to absorb shock loading and more likely to break at the spline or transition of shaft to spline. One piece or two, strength is going to be more about quality of design and materials. Yes the one piece has one less spline to break or wear, but if the transition from shaft to flange is poor, then it’s not good. One piece shafts also require more precision machining and your axle housing and its components better be spot on true (straight etc)
  23. It is a bit concerning. It seems that (by looking at some pictures ), the 3.75 ratio is the worst. (And that’s what I have 🤦🏻‍♂️) I guess they played with tooth size and pressure angles to get their compromise. I would prefer more base material at the root of the tooth, but such is life. Of course it gets thicker towards the centre of crown wheel.
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