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-   -   4L60E trans mount bolts won't tighten up (

Vetteman61 04-01-2012 09:08 PM

4L60E trans mount bolts won't tighten up

I've attempted to install a 4L60E in my 1937 Chevrolet 4 door. I have a transmission crossmember installed from Chassis Engineering, which is for a 700R4 but from what I've learned a 700R and a 4L60E should mount up the same. I bought a mount from a local parts house. I some bolts in but they won't tighten up. Am I supposed to put nuts behind these bolts? The reason I ask is there is so little room inside the mount it doesn't appear there would be room, but I could be wrong. Has anyone used this mount? It's the mount that has bolts that mount into it rather than a single stud sticking out.

In this first picture you can see the bolts sticking up through the bottom of the mount.


Prof. T. Soggmeyer 04-01-2012 09:28 PM

I am pretty sure my mount is the same as yours. In the morning I will take a look and let you know what I see.
Brad...aka soggy

Vetteman61 04-01-2012 09:37 PM

Thanks Brad. I thought that these mounts were supposed to just tighten up so I'd be interested to see what's going on. I could be wrong, that tends to happen a lot.


Prof. T. Soggmeyer 04-02-2012 05:02 PM

Hi Brandon, Mine has nuts on them. It's tight in there, I must have just slid the nuts and washers in there and threaded up into them. Don't really remember though it was a few years ago.

Vetteman61 04-02-2012 06:55 PM

After reading these responses I took the mount back out and realized as was mentioned it was metric and I had the wrong bolts. Went to the parts house and got metric bolts and they now tighten up.


Prof. T. Soggmeyer 04-02-2012 08:50 PM

Seems like all the bolts on these trans are metric it seems.

mmerlinn 04-03-2012 03:51 AM

Using American bolts on any GM inline transmission mount after about 1978 will strip the mount threads. GM converted to metric mount bolts about 1978 even though most of the rest of the transmission bolts did not change until 700s and 4L80Es came out.

350s & 400s - Mount, speedo, and solenoid bolts went metric about 1978. All other bolts were American to end of production.

200s, 200-4Rs, 700s, and all later transmissions had all metric bolts.

SSedan64 04-03-2012 05:13 AM

In the 1st Pic, the Bolt threads look like they're full of Aluminum :pain: , = stripped, so it may be a good idea to use a nut there or Drill/Tap to the next size larger.

Vetteman61 04-03-2012 09:57 AM

Fortunately they tightened up. I just wasn't using my brain. I had used standard the entire time I'd worked on this car because it's a 37 naturally, and the kit came with standard bolts for the ifs, but then when it came time to add new parts I just without thinking was still in the standard frame of mind.


Ripper 410 07-08-2012 11:02 AM

I use these solid mounts all the time, first I check the threads in the tail housing some people like to tighten them with impacts this usually pulls the threads out of the aluminum if it is I put helicoils in then I use new grade 8 bolts or harder and red lock tight, never had a problem and have on just like it on my personal 98 chevy pick up that I drive daily.

mmerlinn 07-08-2012 02:15 PM

You have the WRONG bolts in your mount. You have used AMERICAN threaded bolts when all GM automatic transmission mounts since 1977 require METRIC bolts. You may need to replace the tail housing as you have probably ruined the threads in yours.

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