For the past few days I've been trying to figure out why the passenger side of my LS1 is lower (or vice versa, the driver side is higher) when bolted down. When the motor is bolted in on the driver side, and the oil pan is level on a jack, the passenger side is too high to run the bolt through.

I am running Spohn motor mounts, tubular k-member, and T-56 crossmember. The LS1 has Prothane 7-512 engine mounts, with the longer side to the right (in order to keep the small tabs up, like the directions say). The T-56 mount is a Prothane 7-1604, with the center bolt going through the center hole in the Spohn x-member.

I have removed the clamshells and checked them over to make sure I was installing them the right way, and the Spohn motor mounts only go in one way (can't swap right and left). Could this leveling problem be due to the poly motor mounts, or am I missing something simple?

The first four pictures are when I attached the Spohn motor mounts to the clamshells on the LS1, and then tried to line up the four motor mount holes onto the k-member.

The last two are of when I bolted down the motor mounts to the k-member, the clamshells to the LS1, and was then trying to line up the mounts to stick the big bolt through.

For the record, I'm not knocking Steve or his products; they are built very well. I'm just trying to figure out why the motor isn't level.

 

More pictures.

 

Nothing like spending hundreds of dollars to get a tubular K-member, only to have major problems with it. I feel your pain, even though my K is pre-spohn.

From now on, I am suggesting to everyone who asks, notch a stock k-member and do not waste money on a tubular.

 

Hmmm... that wasn't a very helpful post. The reason to get a k-member is for easy access to the whole motor area (try removing the oil pan with the stock clunky k-member, or getting access to A/C or alternator bolts). I notched the stock k-member and it was horrible. Forget about working easily under the motor.

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I worked on the car some more this morning, and as it turns out, Spohn's stuff was not the problem; the clamshell motor mounts are. Since the engine was wrecked, one of the clam shell mounts is visibly messed up, as the following pictures show.

The first picture is of the mounts side-by-side, and they don't look any different. The second picture is of the mount that was installed on the passenger side, while the third picture shows the mount on the driver side. On the driver side, notice that the gap between the poly bushing and the clamshell is rather big.

The reason why the mount still bolted up perfectly to the motor was because it was on the motor during the wreck (go figure). I know, of course it had to be there, but if it was bent, I thought it wouldn't have bolted perfectly to the motor (so much for flawed logic).

I remembered that one of the clam shell mounts (the pass side) was hard to get the poly mount in, while the driver side (with the gap) was easy as pie. I didn't think of it at the time, but now it makes sense. So, for those of you doing the LS1 swap, buy new clamshell motor mounts, as they could save you some potential headache (and several full days of work) when bolting the motor up.

 

that's what I did but for a reason all it's own. still cost me 108.56 in my hand price pretty high for some rubber and stamped steel

 

Well, the new clamshells are in, and they didn't solve the problem. There was no question one of the mounts was damaged, but the motor is still as crooked as before. I don't know what to do next, except make a big wedge-type shim for the passenger side to get the motor level. However, everything should fit properly...

Has anyone else with a tubular k-member, LS1 motor mounts, and T-56 crossmember (all Spohn) had any problems?

 

Its no big deal in my opinion. Even the factory has shims alllll over the place to line up panels and brackets and whatnot.

Whats the big deal? Loosen the side you need to raise where the k mem and mount plate meet and lift it to where you need it. Measure the distance and add the according amount of shims ( large washers or some plate metal drilled or? ) under the mount plate and bolt it all back down. A little tweaking here or there for alignment should be considered standard fare for any swap let alone one with as many oddball parts as an LS1 third gen swap.

 

Check out the 1st picture in my second post; that's a huge gap, more than there should be for a k-member and motor mounts designed for this swap.

 

True nuff I'd be pissed too if I laid out that kind of coin and had that much gap. I didnt even look at your pics earlier. Still not a big deal to make a 3/4" shim I dont think you have much choice at this point unless you want to make a new horseshoe for the mount? I did my own it was pretty easy. Heck you could just cut and weld spacers in the middle of the mount. Heres a pic to show you what I mean. Do this to both sides of course and if you bevel the edges prior and grind the welds nice when your done it will look clean.

 

Man...mine is off a tad, but not that bad. I choose to just leave mine alone for now. I built my new trans crossmember before I noticed it was crooked alittle. So I decided to just leave it for now. Didnt seem to be causing any issues for the 2500 miles I was driving it. Im using all poly bushings, so its not moving around and hitting things.

Good luck tho, and post up with whatever solution you come up with.

J.

 

I might do that; we'll see what I can come up with this week.

 

I used Spohn mounts on a stock crossmember and my motor sits slightly low on the passenger side. Not enough to hurt anything but I will fix it during next winter when I do heads and a cam swap.

 

As an update to this problem, I drew up some plans and had a shim machined out of 7075 forged aluminum. The LS1 sits level now.

 

Nicely done