seyser Posted February 24, 2018 Share Posted February 24, 2018 This is on a late 80’s R688ST. I know the pic only really shows the shocks but would this be the Mack st34 taper leaf? Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/ Share on other sites More sharing options...
terry Posted February 24, 2018 Share Posted February 24, 2018 You should took the pic exactly between axles, can't see enough. terry Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392754 Share on other sites More sharing options...
kscarbel2 Posted February 24, 2018 Share Posted February 24, 2018 Not a clear picture, but could be a ST34 or ST38 Mack parabolic taper-leaf. Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392755 Share on other sites More sharing options...
seyser Posted February 24, 2018 Author Share Posted February 24, 2018 I didn’t take the pics, I know not much to see. I’m told it’s Mack suspension and it’s not camelback or air ride so I’m thinking taperleaf. Was this a common used suspension? What’s your opinion good or bad? I’ve never heard much about them. Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392756 Share on other sites More sharing options...
kscarbel2 Posted February 24, 2018 Share Posted February 24, 2018 4QK3368AM spring (34,000lb) 4QK3369AM spring (38,000lb) 3AX1993 bolts and 21AX847 locknuts with 8QD261 alignment adjustment collars. Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392759 Share on other sites More sharing options...
blackdog2 Posted February 24, 2018 Share Posted February 24, 2018 A lot of gas company's ran those 3-leaf susp. with the eccentric bushing they broke in half by center-bolt sometimes catapulting truck in to the air . Quote Ed Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392773 Share on other sites More sharing options...
kscarbel2 Posted February 24, 2018 Share Posted February 24, 2018 On 2/24/2018 at 1:03 AM, blackdog2 said: A lot of gas company's ran those 3-leaf susp. with the eccentric bushing they broke in half by center-bolt sometimes catapulting truck in to the air . That was the early version, 1978 thru 1984. We introduced a new mounting arrangement in 1985 (components mentioned above) that corrected the issue you mention. Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392777 Share on other sites More sharing options...
terry Posted February 24, 2018 Share Posted February 24, 2018 Not a good one for heavy duty use. terry 1 Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392782 Share on other sites More sharing options...
Outbehindthebarn Posted February 24, 2018 Share Posted February 24, 2018 I broke one of those grossing 96k once... it was exciting. Rode nice before that though. Quote Fun is what they fine you for!My name is Bob Buckman sir,. . . and I hate truckers. Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392785 Share on other sites More sharing options...
seyser Posted February 24, 2018 Author Share Posted February 24, 2018 So I gather they ride better then camelback but not as heavy duty? Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392806 Share on other sites More sharing options...
blackdog2 Posted February 24, 2018 Share Posted February 24, 2018 11 hours ago, kscarbel2 said: That was the early version, 1976 thru 1984. We introduced a new mounting arrangement in 1985 (components mentioned above) that corrected the issue you mention. Short stanchion or long first we had both I took them off gas delivery put on T-B-A safer . Quote Ed Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392812 Share on other sites More sharing options...
kscarbel2 Posted February 25, 2018 Share Posted February 25, 2018 The ST34 from 1985 rode better than the camelback, was just as heavy duty and had a stellar track record in over-the-road haulage. Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392825 Share on other sites More sharing options...
kscarbel2 Posted February 25, 2018 Share Posted February 25, 2018 Here's a copy of the Safety Campaign, SC176, in which we updated all first generation suspensions to the revised design I spoke of. We didn't sell many of the early version, but the latter version was popular. https://static.nhtsa.gov/odi/rcl/1986/RC-86V009-NN.PDF Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392876 Share on other sites More sharing options...
terry Posted February 25, 2018 Share Posted February 25, 2018 19 hours ago, kscarbel2 said: The ST34 from 1985 rode better than the camelback, was just as heavy duty and had a stellar track record in over-the-road haulage. Is this that 3 leaf tapered spring setup? terry Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392880 Share on other sites More sharing options...
kscarbel2 Posted February 25, 2018 Share Posted February 25, 2018 2 hours ago, terry said: Is this that 3 leaf tapered spring setup? terry Yes, pictured in that link above. Quote Link to comment https://www.bigmacktrucks.com/topic/52606-what-suspension-is-this/#findComment-392891 Share on other sites More sharing options...
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