Danno74Z Posted April 4, 2002 Share Posted April 4, 2002 Aaron, Excellent idea!! This would work in a similar fashion to the JTR idea of running a cable around the front OEM rubber mount. From the pictures above, one can very easily put two bolts through the center of the mount (as you suggest) next to the existing one. This would help add rigidity to the mount (one could tighten the bolts a little) and also in the off chance of failure would support/contain the front of the differential from moving at all. Most transmission mounts probably have 100-200 lbs. on them so a little compression would probably be ok and still dampen vibrations. Naturally, one would still have the latitude to “fine tune†the differential nose for driveshaft angles. Danno74Z Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted April 4, 2002 Share Posted April 4, 2002 This is all good. The safety bolts are a great plan. Anyone want to cut up a tranny mount to see if it is interlocking? Maybe someone digging through a jy this weekend can grab one and check it out? Pete, yes, I was planning on keeping the vertical brace piece in the "bent" design. If I weld it on the back of the "U" instead of where it is on yours, will it interfere with anything? I wasn't aware that the e-brake mechanism trouble was over the tranny mount stud/nut area. It looks like from the picture that the problem area is to right. I haven't crawled under to take a closer look at that area yet. I was just going by your pic. If that's the case than lowering that side makes no sense. Straiten me out on this Pete. Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 4, 2002 Author Share Posted April 4, 2002 Originally posted by Dan Juday:This is all good. The safety bolts are a great plan. Anyone want to cut up a tranny mount to see if it is interlocking? Maybe someone digging through a jy this weekend can grab one and check it out? Man, those things are not cheap! If somebody has a torn up old one, that'd be cool. Pete, yes, I was planning on keeping the vertical brace piece in the "bent" design. If I weld it on the back of the "U" instead of where it is on yours, will it interfere with anything? No, I don't think so. I wasn't aware that the e-brake mechanism trouble was over the tranny mount stud/nut area. It looks like from the picture that the problem area is to right. I haven't crawled under to take a closer look at that area yet. I was just going by your pic. If that's the case than lowering that side makes no sense. Straiten me out on this Pete. Good point. Initially, I was concerned about the stud/nut. But in retrospect, the e-brake u-shaped cable guide is in it's rearward most position (on my car at least - I have non-OE e-brake calipers on my car though) in the released position, and only moves forward with the e-brake applied. So there's not really much danger of the mount stud/nut interfereing with the cable guide. So yes, there's room on the driver's side (US driver that is) of the stud to put that extra limiting bolt through the mount. I wouldn't tighten it though, as you'd be effectively shorting out the damping the mount provides. Quote Link to comment Share on other sites More sharing options...
jeromio Posted April 5, 2002 Share Posted April 5, 2002 I know that the mount that came with my 4L60E on my LS1 is interlocking. But it's actually easy to see with that one since it's sort of a different design. I would be very surprised if the GM mount was NOT interlocking as it's very easy to do with the simple pressed steel pieces that are used in it's construction. But then, the Datsun unit is not interlocking. You know, they must've just like Mr.K's Nephew work on that aspect of the car. That front diff mount - there is absolutely nothing good to say about it. Oh, I am the other guy who did the DeGroot style mount. I am very happy with it and it is undoubtedly completely bulletproof. It was more difficult to construct though (http://240z.jeromio.com/diffmount). This one looks lots easier to fabricate. Although, if there are issues with EBrake cable routing, the DeGroot mount might be a better solution. Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 5, 2002 Author Share Posted April 5, 2002 I thought it might be you who also did the DeGroot mount. The ebrake issue is trivial and easily fixed with a spring. I just wanted to point it out as something you needed to be aware of if you did this mod. Quote Link to comment Share on other sites More sharing options...
Guest Aaron Posted April 5, 2002 Share Posted April 5, 2002 I have an easy fix for the tension loads on this or any other mount. I have personally used this on several motor mounts with good success. I am assuming that the trans mount you are using is essentially two metal plates with rubber bonded between them. In a location on the mount where id does not interfere with anything else, drill a hole all the way through the mount for a 5/16" or 3/8" bolt to pass through. Put a lock nut on the bolt and leave it just a little loose. This allows the mount to work as it is supposed to, but when stretched far enough, the bolt takes the load and the mount does not separate. Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 5, 2002 Author Share Posted April 5, 2002 Dan, I like the idea of a bent peice too. But the stiffener across the top is a good idea to keep. It could be done on a cross piece too, and put at the back of the bracket more easily. But there's really no room to move away from the parking brake mechanism - it's right above the mount. If you lower the top of the bracket, it would lower the front of the diff too far - I think the pinion center line is about 1 degree nose-up on my install. Much lower and I'd be afraid that the front seal would have too much gear oil against it if the gear oil was high enough in the rear to do it's job. Aaron, I like that idea. Theres a bit of room on the top of the diff to put a countersunk bolt head up through the mount. But another bolt/nut up above the mount bracket where it'd have to be is yet another thing to interfere with the parking brake mechanism. This may be moot, as I thing the GM mount is interlocking anyway. Anyone know? It's the same one that JTR recommends for use as a tranny mount. Quote Link to comment Share on other sites More sharing options...
Oltmann Posted April 20, 2003 Share Posted April 20, 2003 I'm bringing up this old thread to note that on my 71, Ron's design will not work as is. The differential belt bracket is apparently much narrower than it was in later years, and the forward most threaded hole falls roughly in the middle of the bracket.My car originally had the diff. that sat an inch forward, so I believe this is the reason for the difference. I plan to weld nuts in the forward locations used in later years, and I will update this thread again once I've finished. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted April 24, 2003 Share Posted April 24, 2003 Hey all.... I had this peice made a few months ago and I'm just now getting around to installing it. My question is, once I put the metal brace up into place, I measure the space between the top of oem cross member and the new brace where the GM mount hole is and come up with around 4.5 inches. If I bolt the cross member onto the diff, then put the new GM mount onto the top of the diff, I come up with 5 5/8 in. needed. My thought is that this aftermarket urathane (sp) GM th350 mount is to thick??? Is there a certian GM trans mount that I should've gotten....? BTW thanks Ron Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted April 25, 2003 Share Posted April 25, 2003 If I understand you right J. it sounds like you are tring to use both the stock and the Ron Tyler mount. You can't do that. Leave out the stock mount and it will fit fine. The R.T. mount locates the nose of the diff a little lower than stock. This faciltates better driveshaft u-joint angles if you have a V8. If I misunderstood you, and you already know all of this, sorry. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted April 25, 2003 Share Posted April 25, 2003 Thanks for the responce... OK, if I understand this right, I am to leave the mount off the bottom of the diff, and hard mount it to the crossmember? If this is correct, how does this allow the diff to flex upward? I made the previous measurement with the oem diff mount on the diff, but removing it and letting it sit on the x member, wouldn't allow it to move any. Am I missing something? thanks joel Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted April 25, 2003 Share Posted April 25, 2003 Don't mount it to the crossmember at all. It simply hangs from the Chevy tranny mount. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted April 25, 2003 Share Posted April 25, 2003 Ahhh...... I guess I didn't notice that it has been posted above... :malebitchslap: I'll lay that way out and see how it goes. Are there any certian amount of washers that should be used between the diff and the bottom of the mount? mine isn't concaved on the bottom of the mount for it to fit the round shape of the diff case. thanks again Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted April 26, 2003 Share Posted April 26, 2003 Well, I just finished up the mount swap. Here are a few pics of the RT brace and the TH350 trans mount on it. If you look hard enough, you may see what was said above about the emergency brake peice being close to the bolt that holds the new mount. I also had to remove the spring, but everything else was fairly simple... Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted April 30, 2003 Share Posted April 30, 2003 Thanks for the pics Joel, looks good. Quote Link to comment Share on other sites More sharing options...
Greg SmileZ Posted May 31, 2003 Share Posted May 31, 2003 Can the Ron Tyler solution be installed without removing the diff? Quote Link to comment Share on other sites More sharing options...
Guest Your Car is Slow Posted June 1, 2003 Share Posted June 1, 2003 So was it ever mentioned that someone would make these for retail sale? Or is it still purely a do it yourself gimmick? Could the bracket be made out of aluminum? Quote Link to comment Share on other sites More sharing options...
ianz Posted June 10, 2003 Share Posted June 10, 2003 Good thread guys, I too have incorporated this mount on my late 71 240....... I made mine simpler than the drawings with just 3 plates 1/4" thick mild steel with thick weld fillets.....but the plate lengths and angles in the drawings were dead on. The bolt holes for the strap threw me a little, but I was able to measure and drill to incorporate the stock hole pattern on the diff mount. Be aware of this on the 240s. I actually drilled the side plate holes, bolted the side plates in the tunnel with the top plate resting above them and tack welded it together. The fuel lines on the 240 also presented a slight problem, as did the eBrake cable, but both were minor I bought the urathane tranny mount from pep boys for $22 (it varifies that its interlocking right on the package) and had to modify the slots to work with an R180 (they were too wide) and ground the urathane nubs off the bottom of the mount so the plate would sit flush on the top of the diff. The tranny mount bolt is VERY stout (3/8" at least) so I am not worried about it comming apart on me...... my car has a stock 280 motor with an 180 LSD rear (Solo 2 BSP specs) and I have had this mount in the car for 3 months with no apparent problems (solid and quiet!!) I have a vibration that comes on at or above 70mph but do not think its dif mount related.... I REALLY like this tranny mount especially after just helping a friend replace his cracked cross member (caused by prolonged use of solid diff mount) Thanks to the designer!! Cheers Ian PS I have pics of mine installed in the 240 if anyone wants to see them, just email me..... Quote Link to comment Share on other sites More sharing options...
ianz Posted June 10, 2003 Share Posted June 10, 2003 By the way, if you are using CV half shafts, using this diff mount accentuates the tolerance issues between the rear swaybar, swing arms, body and half shafts by limiting the swaybar travel (hits the diff before droop)...so be aware!!! Quote Link to comment Share on other sites More sharing options...
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