powerglide to th350 conversion

[mikefam]

I recently converted my 68 convertible from the powerglide transmission to a th350 and would like some input from anyone who has done the same. The conversion was almost a straight up bolt in swap with a couple of exceptions. I found everything that I needed to hook up the horseshoe shifter and kick-down cable at Shiftworks and I thought that I was all set until yesterday when I went underneath to look for a tranny leak and noticed that the rear motor mount cross-member covers the two rear drain pan bolts on the tranny and it looks just about impossible to get a wrench on them.  It looks like I may even have to unbolt the rear mount and lift the engine to get the pan off.

Has anyone ever seen this and how did you deal with it? Any input would be be appreciated.

Mike.

[click]

Mike if its like this pic of my setup, my mechanic torched away the lower lip of the engine mount to give access to the pan bolts on the 700r I had installed. If you are not concerned with 'originality' of the mount, it might be an option for you.

[mikefam]

Yeah I didn't want to cut the mount but it is probably the only thing to do. I hate cutting a part that has survived almost fifty years. I was also thinking of drilling two holes that align with the bolt heads so that I can get a socket wrench on them but I'm not so sure that the pan will slide out of there. It is very tight.

[jims69]

It's a pain.  What else can I say?   My 350 with TH350 came from the factory new and the cross member does cover the rear bolts on
the transmission pan.   It's necessary to improvise; place the broad side of a chunk of 2X4 under the pan easing it up slowing after
removing cross member and mount bolts, move the cross member back slightly to gain access to the bolts, block the whole thing
in that position and remove the pan.  Fortunately it doesn't have to be done often.

[mikefam]

Jim:

Wow it's hard to believe that GM built them that way. I'm leaning towards drilling a couple of holes to allow me to get a socket wrench on the bolts and then see if I can wiggle the pan out of there once the bolts rare removed. I don't need to remove it right now so I have time to think about it.

[jims69]

It fits together;  that must have been GM's goal at the time.  Its just one of those things that makes one wonder what they were thinking.  The original transmission pan; has a drain plug, but yet the cross member prevents easy access to the transmission filter!  It's a real  mess to change both; the design  made an easy thing into a really irritating drippy mess. 
I've owned the car since I was 18 and  still recall my thoughts the first time under the car............."What the "
Over time I've decided they got 99% of the car right, this is just something that could have been a better design on the cross member.

[mikefam]

It fits together;  that must have been GM's goal at the time.  Its just one of those things that makes one wonder what they were thinking.  The original transmission pan; has a drain plug, but yet the cross member prevents easy access to the transmission filter!  It's a real  mess to change both; the design  made an easy thing into a really irritating drippy mess. 
I've owned the car since I was 18 and  still recall my thoughts the first time under the car............."What the "
Over time I've decided they got 99% of the car right, this is just something that could have been a better design on the cross member.

Thanks for the info, I'm glad to hear that it is possible to get the pan on and off but how do you get a wrench on the bolt heads?

[jims69]

There is enough space between the floor of the car and the top of the  frame rail to get a wrench in there; then a socket with an extension through the
hole in the frame rail to get the bolt head from underneath.  I use a punch or long screw driver to re-align the holes for the bolt upon re-assembly.

It's not a bad job; it just annoys me because it has to be done this way; taking the bolts out of the cross member and transmission mount to ease the
thing back to get to the rear pan bolts.   Over the years I've learned to use as big of a drain pan as possible, and  have lots of shop towels at the
ready.  Good luck       Jim

[janobyte]

Try a fluid extractor to draw most of it out the dipstick tube.