Timmyb Posted October 4, 2016 Share Posted October 4, 2016 How do you identify 34k suspension vs 38k? I've pulled my rear end out, My front diff is 38k andmy rear diff is 44k. I assumed the suspension was 38k but guy working on it thinks it's a 34k. Is there a way to identify them visually? Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/ Share on other sites More sharing options...
terry Posted October 5, 2016 Share Posted October 5, 2016 34k and 38k rears main difference is number and thickness of the spring leaves, And spring pads and caps. 34k,38kand 44k diffs are all the same. terry Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-347861 Share on other sites More sharing options...
Timmyb Posted October 5, 2016 Author Share Posted October 5, 2016 I have read elsewhere that 34k used aluminium components, was this strictly the case all th time? Mine is all steel/iron so is this an indication it may be 38k? By diffs I meant rear housing is cast and front housing is fabricated. Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-347879 Share on other sites More sharing options...
steve p Posted October 5, 2016 Share Posted October 5, 2016 34 /38 fabricated housings 44 and up are all cast housings 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-347892 Share on other sites More sharing options...
terry Posted October 5, 2016 Share Posted October 5, 2016 I have seen a 38 and a 44 housings on the same tandem before. terry Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-347920 Share on other sites More sharing options...
Vladislav Posted October 19, 2016 Share Posted October 19, 2016 There's also difference in rear hubs. At least the ones with 8 stud shaft flanges exist (small flanges) and the six stud larger flanges. With different bearing inside. I supposed to see big hubs with cast banjo's and small ones with stamped steel (fabricated). But recently found on at least two RD690's fabricated banjo housings with big 6 stud hubs. And if the difference between 34K and 38K is springs only how to determine it for an air ride? 1 Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-349245 Share on other sites More sharing options...
Timmyb Posted October 19, 2016 Author Share Posted October 19, 2016 Vlad, you're right. I was told 34k diffs use a 5 spoke hub and 8 bolts on axle. Same guy told me 38k use 6 spoke hub and 6 bolts for axles, but I've seen 6 spoke hubs with 8 bolts in axle. I've found part numbers for 38k springs in this conversation here- Also, the narrow part of the housing that goes to wheels is a bit different. 34k is round and 38k is more squared (so I was told). 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-349251 Share on other sites More sharing options...
kscarbel2 Posted October 19, 2016 Share Posted October 19, 2016 Timmy, did you look for the Mack 4QK part number stamped on the top of the "T" on the main leaf? Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-349253 Share on other sites More sharing options...
Timmyb Posted October 19, 2016 Author Share Posted October 19, 2016 Yeah I sure did. It reads 4QK4001A. Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-349260 Share on other sites More sharing options...
terry Posted October 20, 2016 Share Posted October 20, 2016 5 hours ago, Vladislav said: There's also difference in rear hubs. At least the ones with 8 stud shaft flanges exist (small flanges) and the six stud larger flanges. With different bearing inside. I supposed to see big hubs with cast banjo's and small ones with stamped steel (fabricated). But recently found on at least two RD690's fabricated banjo housings with big 6 stud hubs. And if the difference between 34K and 38K is springs only how to determine it for an air ride? A full 44 rear used to be the cast housings and six spoke hub, a 38 is the fabricated housing with the five spoke hub, and the only difference in a 34 and 38 were the number and thickness of the springs. terry Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-349262 Share on other sites More sharing options...
Vladislav Posted October 21, 2016 Share Posted October 21, 2016 On 20.10.2016 at 3:09 AM, terry said: A full 44 rear used to be the cast housings and six spoke hub, a 38 is the fabricated housing with the five spoke hub, and the only difference in a 34 and 38 were the number and thickness of the springs. terry Thank you for explaining that. Sounds easy to figure out and keep in mind. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-349489 Share on other sites More sharing options...
Timmyb Posted November 2, 2016 Author Share Posted November 2, 2016 Turns out I have 38k anti sway springs. They are good yeah? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47153-identify-34k-38k-suspension/#findComment-350675 Share on other sites More sharing options...
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