UA-65274002-1 Jump to content
Quaraxkad

L67 swap engine crooked!

Recommended Posts

Starting a new thread for this issue, since I figure a lot of people probably don't read through the long build threads.

I have an L67+4T65E-HD swapped in place of an LH0-3T40 in a '92 Cutlass. All bolted up, the engine is rotated a few degrees clockwise (standing in front looking from above). Note the dogbone mounts don't line up with the holes on the upper radiator support.

20190330_203809.jpg

Now with the brackets bolted to the radiator support, you can see how far off the engine mounts are when at rest.

20190423_183856.jpg

20190423_183908.jpg

If i loosen up the mounts and wiggle things around, it IS close enough to force-fit it in place, but that's not really a solution, and doesn't solve all the problems anyway. For starters, all it does is apply a heavy preload to the dogbone mounts and doesn't fix the position of the engine. So the axles are never straight, and the exhaust downpipe doesn't fit through the exhaust channel in the firewall. This next image is even misleading, because for this pipe to even fit in that channel, the flexible joint at the top is almost fully stressed.

20190423_185448.jpg

 

I *thought* this might be due to the transmission mount issue I ran into. Short version: The 3800 transmission mount has different bolt spacing that didn't fit in my sub-frame, so I swapped it out with a brand new '92 3T40 mount, which fit both the 3800 transmission bracket and the Cutlass sub-frame. This 3T40 mount however is 10mm taller than the 4T65e mount.

20191026_124744.jpg

So I experimented a little more today. I supported the engine with a hoist, put the dogbones in place, and tried to find a place where the engine could rest comfortably. I cut out a 67mm block of wood to put between the transmission mount and sub-frame bracket, and this is where the engine feels like it can rest and appears to be relatively straight.

20191026_145957.jpg

As you can see, both bolt holes on the transmission bracket are significantly farther back than the holes in the sub-frame bracket. So this appears to be more complicated than a mount that's just 10mm too tall. The LH0 that came out was perfectly straight and never had an issue like this. As far as I know there isn't any frame damage that could have shifted things out of alignment.

I need to get this car back on the road, as I might be moving soon and will need a daily driver since my new home won't be within walking distance of my day job! I've tried loosening all the subframe bolts, all of the engine mount bolts, shifting things around, it just will *not* straighten up. I really have no idea how to proceed from here. Anybody have any ideas?

Share this post


Link to post
Share on other sites
3 hours ago, Quaraxkad said:

...I *thought* this might be due to the transmission mount issue I ran into. Short version: The 3800 transmission mount has different bolt spacing that didn't fit in my sub-frame, so I swapped it out with a brand new '92 3T40 mount, which fit both the 3800 transmission bracket and the Cutlass sub-frame. This 3T40 mount however is 10mm taller than the 4T65e mount.

So I experimented a little more today. I supported the engine with a hoist, put the dogbones in place, and tried to find a place where the engine could rest comfortably. I cut out a 67mm block of wood to put between the transmission mount and sub-frame bracket, and this is where the engine feels like it can rest and appears to be relatively straight.

As you can see, both bolt holes on the transmission bracket are significantly farther back than the holes in the sub-frame bracket. So this appears to be more complicated than a mount that's just 10mm too tall. The LH0 that came out was perfectly straight and never had an issue like this. As far as I know there isn't any frame damage that could have shifted things out of alignment.

 

Wild Guess:  Your subframe has engine/transmission mounting holes in different locations than the donor-car's subframe.

Share this post


Link to post
Share on other sites

Interesting....

what vehicle did you source for the L67 mounts?..(all of them)...the only Gen 1 platform to make use of the L27 powertrain would be a 91-96 Buick Regal & the part #'s for the mounts varied thru those years.

Those dogbones you're making use of look like Gen 2 items, not Gen 1 platform pieces. There should be an alloy *torque strut/dogbone* between the rad header & the engine support

Edited by 55trucker

Share this post


Link to post
Share on other sites

The engine is from a 2004 Impala SS. It came with all mounts still attached, but the passenger side mount was no good. So I replaced it with a brand new one from Rock Auto for the same car. The drivers side mount as shown above in the comparison is the original 04 Impala SS vs a brand new 92 Cutlass.

If I remember correctly, the dogbone brackets in the first picture are from the very same Impala. They are the kind that wrap around the bottom of the upper radiator support. After installing the Cutlass radiator I realized they would not work because the radiator blocks access to the under side of the upper radiator support, so I got a pair of brackets from a 98 Lumina as seen in the second two pictures.

Edited by Quaraxkad

Share this post


Link to post
Share on other sites

I'm guessing you meant to refer to the original trans as the 440t4,

that trans, the 4T60 & the 65 all make use of the same large support bolted to them, the only difference depending on the platform the powertrain is fitted into are the mounts. My feeling is that you should be using everything from the 1st Gen Regal.

The same with the dogbones, you already have the two original rad header/strut supports that were part of the LH0 powertrain, you need two dogbones for the Regal 3800 (that engine in the early Regals only made use of one dogbone), so you require one more as well.

I take it that you already have the correct engine mounts(2) for the '92 Regal/3800.

Share this post


Link to post
Share on other sites

I did mean 3T40. it was originally called Turbo-Hydramatic 125 but later renamed to 3T40. 440t4 is the 4T60 which I did not have in the Cutlass originally. Unfortunately I no longer have the engine and transmission that came out *years* ago, it was scrapped for garage space once I thought I had everything off of it that I would need. Now I wish I could go back and examine its mounts and mounting points.

I looked up 92 Regal 3800 mounts, the transmission mount is the same as the solid rubber 77mm one pictured above so I already have that. The engine mount is definitely different and may or may not fit into my subframe. This is what the currently installed Impala 3800 and original 92 Cutlass LH0 mount looks like:

2796__ra_p.jpg

And how it fits into the subframe:

20190326_172923.jpg

This is what the 92 Regal mount looks like:

A2697HY_22__ra_p.jpg

A2697HY_17__ra_p.jpg

It looks like the bottom bolts should line up with the unused holes in my subframe. And the top bolts are offset from center, which if aligned properly, might rotate the engine counter-clockwise back to straight! It's definitely worth a shot, I'll see if I can pick one up today! If this doesn't work, what are the chances it's a different subframe and I'll have to swap it out with a junkyard pull?

I will also look into the 92 Regal dogbones, but they may not be necessary if this engine mount straightens things up.

Share this post


Link to post
Share on other sites

I may have spoken too soon... A closer look at the Regal mount, the bolts are *not* offset. the top two are directly above the bottom two, so if this mount fit in my subframe it would not rotate the engine in either direction.

Share this post


Link to post
Share on other sites

A few thoughts:

your car or the donor car, were they ever wrecked? 

are you purchasing mounts for a 98' Lumina since that would be technically the closest match, no I didn't do wherever research is necessary to look at the interhcange

You mentioned that you had a 3t40 3 speed before this.... since that is the most unusual component in the mix since most people go from 4t60 or 4t60e to 4t65 is it possible that the transmission mount bracket that is bolted to your subframe is offset different from what we are expecting? I'm just spitballing here since I don't have my parts manual on hand that would tell me definitively if that part is specific to the 3 speed cars or not.

I don't think that regal mount will be of any use to you I think the L27 mounted completely different then the L36 W bodies did later on. 

i'm thinking it ultimately is 2 issues, wrong mounts, as both the LH0 and L67 mounts may be wrong, see my comment about buying ones for a 1G that did come with a L36, and I have a feeling that the mount for the 3 speed cars might be shifted to accommodate mounting for that. If I remember I'll get out a parts manual and check tonight.

Share this post


Link to post
Share on other sites
45 minutes ago, White93z34 said:

A few thoughts:

your car or the donor car, were they ever wrecked? 

are you purchasing mounts for a 98' Lumina since that would be technically the closest match, no I didn't do wherever research is necessary to look at the interhcange

You mentioned that you had a 3t40 3 speed before this.... since that is the most unusual component in the mix since most people go from 4t60 or 4t60e to 4t65 is it possible that the transmission mount bracket that is bolted to your subframe is offset different from what we are expecting? I'm just spitballing here since I don't have my parts manual on hand that would tell me definitively if that part is specific to the 3 speed cars or not.

I don't think that regal mount will be of any use to you I think the L27 mounted completely different then the L36 W bodies did later on. 

i'm thinking it ultimately is 2 issues, wrong mounts, as both the LH0 and L67 mounts may be wrong, see my comment about buying ones for a 1G that did come with a L36, and I have a feeling that the mount for the 3 speed cars might be shifted to accommodate mounting for that. If I remember I'll get out a parts manual and check tonight.

 

 

I was thinking the same as Chris.  Is the lower bracket that is attached to the subframe different, and or installed in the correct holes in the subframe(I'm not sure if that's possible), but I do wonder if it is that bracket that's causing the issue.  

 

Share this post


Link to post
Share on other sites
6 hours ago, Quaraxkad said:

I did mean 3T40. it was originally called Turbo-Hydramatic 125 but later renamed to 3T40. 440t4 is the 4T60 which I did not have in the Cutlass originally. Unfortunately I no longer have the engine and transmission that came out *years* ago, it was scrapped for garage space once I thought I had everything off of it that I would need. Now I wish I could go back and examine its mounts and mounting points.

I looked up 92 Regal 3800 mounts, the transmission mount is the same as the solid rubber 77mm one pictured above so I already have that. The engine mount is definitely different and may or may not fit into my subframe. This is what the currently installed Impala 3800 and original 92 Cutlass LH0 mount looks like:

 

And how it fits into the subframe:

20190326_172923.jpg

This is what the 92 Regal mount looks like:

 

 

It looks like the bottom bolts should line up with the unused holes in my subframe. And the top bolts are offset from center, which if aligned properly, might rotate the engine counter-clockwise back to straight! It's definitely worth a shot, I'll see if I can pick one up today! If this doesn't work, what are the chances it's a different subframe and I'll have to swap it out with a junkyard pull?

I will also look into the 92 Regal dogbones, but they may not be necessary if this engine mount straightens things up.

Like the LQ1 DOHC engines the L27's made use of two engine mounts (a front & rear) the engines do not roll, the later L36 1st gen engines did roll as there was only a single engine mount under the front cover. There would be two brackets that are attached to the L27 block that *place* the forward & rear mount, those mounts slip down into the same openings in the subframe that the two mounts that hold up the LQ1 engine do.

I take it that the original 92 subframe is still in the car?

Edited by 55trucker

Share this post


Link to post
Share on other sites

So I pulled out my Pontiac parts manual... I only have Lumina and Grand Prix but that crap is all the same, it looks like all automatic transmissions got that bracket on the subframe, 3 speed and both the 4t60 / E got it. so that rules that out.

What is the transmission bracket on the trans from?

Share this post


Link to post
Share on other sites

To answer a few questions posed: As far as I know, neither car have been in accidents. The engine mount for the 98 Lumina is the same as what I have. The 98 Lumina transmission mount is not the same part number but looks the same as the 3800 mount. Judging from photos alone, I'm pretty sure it has the same bottom bolt pattern as the 3800 which wouldn't fit in my subrame without drilling new holes in the bracket. Yes, the Cutlass has the original subframe. The bracket on the transmission is from the 04 Impala. I *had* two other transmissions, both from 97 GTP's. They appeared to be the same bracket but I don't have them to compare anymore.

EDIT: I just found one of the 97 GTP transmission brackets, and it is the same.

Edited by Quaraxkad

Share this post


Link to post
Share on other sites

Your wood block picture = you need a bracket from another W' to accomplish that spacing or you need to drill your current one.

 

Here's a '94 bracket in a car w/ a 3800 for example: Click thumbnails for full size.

 

IMG-1526-1.jpg IMG-1527.jpg

 

 

Edited by mfewtrail

Share this post


Link to post
Share on other sites
5 hours ago, mfewtrail said:

Your wood block picture = you need a bracket from another W' to accomplish that spacing or you need to drill your current one.

 

Here's a '94 bracket in a car w/ a 3800 for example: Click thumbnails for full size.

 

IMG-1526-1.jpg IMG-1527.jpg

 

 

Winner!  Great picture Matt!  Definitely shows the difference between the mounts that bolt to the sub-frame!  

Share this post


Link to post
Share on other sites
5 hours ago, mfewtrail said:

Your wood block picture = you need a bracket from another W' to accomplish that spacing or you need to drill your current one.

 

Here's a '94 bracket in a car w/ a 3800 for example: Click thumbnails for full size.

 

IMG-1526-1.jpg IMG-1527.jpg

 

 

Whaat!? There are 4 holes in that bracket!! Wow, that certainly looks like my solution!

Now the problem becomes removing that bracket from my car without having to pull the engine... I did try once already and was able to start loosening all but one bolt. That last one I was able to get a wrench on but didn't have any clearance to turn it. I'm thinking I shouldn't have much trouble getting a new one at the junkyard, there's bound to be one that someone's already pulled the engine from.

Thank you so much for that picture. I've been stuck here for months now, unsure of what to do!

Share this post


Link to post
Share on other sites

Mission complete!! I went to the junkyard today and found three cars with that mount. 1997 and 1999 Lumina, and a 1994 Grand Prix, All of them still had engines, I was hoping to find one that someone already pulled the engine from. Turned out to not be all that difficult to remove anyway, I just jacked up the engine with the scissor jack I found in the trunk (because they wouldn't let me bring in my own scissor jack!) and unbolted it.

Comparison of the original mount on bottom and the new one:

20191103_144635.jpg

Notice the two holes for the subframe bolts are differently spaced. Fortunately my subframe had an additional hole there, so it fit with no trouble at all.

20191103_150000.jpg

Dogbones unhooked, engine mounted and off the hoist, everything just "at rest". Perfectly lined up!!

20191103_145944.jpg

20191103_145948.jpg

Thank you, mfewtrail!

Now on to the next mystery, exhaust. New thread coming soon...

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...