Th350 removal

[TJ1978]

My bells housings bolts are metric 10x1.5
Correct? Did GM mix standard and metric on the same vehicle?
Lowes didnt have what I need... have to venture to ACE hardware

 

[Wes Harden]

Iirc all gen1 smb are 3/8 16.

 

[imiceman44]

Iirc all gen1 smb are 3/8 16.

Yeah and for those 4 bolts I found some flanged bolts but good washers would work too

 

[TJ1978]

Iirc all gen1 smb are 3/8 16.

Right, but when I put the bell housing bolt in that size at Lowes to double check size... they didnt fit so I went to the metric threads and it fit perfectly.

So I dont know what to buy to now or its my mistake? hahahahahah

Either way I have to go to Ace to see if they have anything for my tranny adapter, Ill check again at AcE, th bell housing bolt size.

 

[Wes Harden]

Can we see a picture of said bellhousing bolt top of hex head pls

 

[Wes Harden]

Personally I reuse bellhousing bolts all the time. Only reason I would replace if damaged or lost

 

[TJ1978]

Sure. I was going to reuse them but they are different lengths so I want them to be correct.


I have 6 total... 4 are the same while the other slighty shorter are the same as each other but different than the other 4.... jeez i hope that makes sense? Haha

First hex top picture is the longer 4
Second hex top is the shorter 2

 

[imiceman44]

Sure. I was going to reuse them but they are different lengths so I want them to be correct.


I have 6 total... 4 are the same while the other slighty shorter are the same as each other but different than the other 4.... jeez i hope that makes sense? Haha

First hex top picture is the longer 4
Second hex top is the shorter 2

View attachment 329557

View attachment 329558

View attachment 329559

They are supposed to be different lengths.
I can't remember which are shorter but I know the one that holds the transmission dipstick tube towards the top of the transmission is longer.
I want to say the bottom 2 are shorter.

 

[TJ1978]

I assumed so but was confused, as usual... I wasn’t positive as I didnt pay attention when removing them, where the different sizes went nor that there were different sizes.
Which is why when I did notice the sizes, I thought I mixed something up before bagging them... hahahahahaha.

I have no problem re-usuing these as I kind of want to get moving a bit quicker on this.

 

[Wes Harden]

also those are NOT metric, sae 3/8 16 grade 5

 

[TJ1978]

also those are NOT metric, sae 3/8 16 grade 5

Right... what threw me off, was them not fitting in that thread board they have at Lowes, the were slightly small.

I had the new bolt baggy in that size and thought lets just check.
Anyway... hahahah
Im heading to ACE tomorrow

 

[TJ1978]

@Wes Harden
Do you happen to remember or know where the smaller two bell housing bolts go? The four longer ones go along the top correct?

By the way, thanks for sticking with this thread and all the advice and suggestions you’ve provided. I do appreciate it.

Same to @imiceman44

 

[diesel4me]

Usually metric bolts will have metric hex and stamped with 8.8 or 9.8 ,the strength rating similar to grade 5 or 8 SAE bolts..

SAE bolts will have 3 lines on the head to indicate grade 5,and 6 lines to indicate grade 8..

Every pre '87 SBC I have had to remove bell housing bolts from were 3/8 x 16 course thread,but I wouldn't be surprised if GM used metrics on some later ones,my 82 GMC has a mixture of SAE and Metric bolts,makes repairs more frustrating,especially when the metric bolts "almost" match up with SAE threaded holes,like the alternator bolts,15mm head and 10 mm threads,its easy to strip a 3/8" by putting the wrong bolt in a hole..

Most of the transmission bell housing bolts I've removed were 1-1/4" long,the one for the dipstick is sometimes a threaded stud with a hex ,that has another 1/2" of thread past the hex to attach the dipstick tube to with a nut..

 

[Wes Harden]

I think the short ones are the top 2. Little more clearance, and no brackets.

 

[TJ1978]

With all that said, does anyone know the torque spec for the adapter bolts?

 

[imiceman44]

With all that said, does anyone know the torque spec for the adapter bolts?

I usually go snug then 2 uga uga

 

[Wes Harden]

lol Ice

German virgin Guttentight

no is 35 foot pounds, tighten them all down evenly.

 

[wasted wages]

4 studs go in the back of the trans, you may have to run a tap in them to allow them to pass all the way thru. locks and nuts on the back side where they will extend thru the transmission case flange.

the 4 holes in the adapter are not threaded.
slide the adapter over the studs, install locks and nuts. locktite everything and torque everything to spec. Don't forget the o-ring or gasket..

Then continue with the installation as normal....

As I said, it's up to you as if you want to do this...but as you can see these are the only 4 bolts that hold that big ass transfer case to the trans. I do it this way after seeing several transfer cases fall out of trucks with T-350's

 

[TJ1978]

i get exactly what youre saying. I just dont think I want to mess with it. Running tap, studs, washer and nuts etc. I have enough on my plate to fumble through and hope for as little hiccups as possible. Plus I have no more money and I already have the GM bolts for the adapter.

 

[diesel4me]

It's important to retain the torque bar that bolts to the transfer case and goes to one bell housing bolt,to aid in supporting it--I see a lot of lifted trucks that had it removed ,because they lowered the transfer case to help with u-joint angle issues,and that lets all the weight and load get put upon those 4 adapter to transmission case bolts..not uncommon to have the TH350's tail bust off just after the adapter after a off road excursion,especially if you got it airborne,if that bar isn't left on..