Topic: Manual transmission rebuild

[hammy221]

So as I post a while back my synchro gears for 2nd are gone in my trans and well I decided to go with a junkyard used one for now. I haven't bought it yet but will be soon unless someone here has a better solution for me. Not sure but if anyone has rebuild the ar5 trans can you please let me know how involved it really is. Also I'm looking at doing a big hp build for my solstice in the 400-450 whp range and would like to build up the trans Im taking out is I can install it with the rebuilt engine. With that being said what are the off the self options to beef up the ar5.

[Carbon Sky]

I have not rebuilt the ar5, but I have rebuilt multiple FWD, RWD and AWD transmissions and differentials.  I have also rebuilt multiple engines, and in my opinion, transmission are far more complicated/difficult.  I have not rebuilt an auto transmission, with the planetary gears and what not, so I have no experience there.

If there are some general tips I can help with, it is MEASURE EVERYTHING.  If there is a specification given, meet it.  Whether it be freeplay, preload, resistance, etc.  If you don't have the proper measuring tools.  Buy them, you'll use them again.  At a bare minimum, you'll need a highly accurate caliper (some prefer digital, but maybe I'm old school in that I like mechanical), a dial gauge, a shop press, various sizes of 2 and 3 jaw pullers, and either braising tools, or a cheap welder.  I have often had to weld together threaded sections of bolts to a mounting plate, that was adjustable, and rigid, so that I could mount a dial gauge to properly measure for free play, because those magnetic bases won't do ish on our cast aluminum cased ar5.  I've also welded together unusually shaped press cups.  I'm assuming you already have feeler gauges.

Put it this way, at one point, I rebuilt a FWD transmission.  Four plus years later when I sold the car, the transmission was still perfect.  A friend with the same year, make, model, trim level, etc, car, rebuilt his transmission.  He had ever on going problems with it.  To this day, if he forces it into R a little too aggressively, the transmission locks itself in a forward gear, and reverse.  All he has to do is pull the reverse sensor plug, and tap it free, but what a headache when it happens.  Put it this way, he wasn't as anal retentive about all the specifications.  He's a very accomplished auto mechanical guy.  He went to college for it for 2 years.  And has done very good work.  But this is the difference if you don't take measurements that you're supposed to.

As for beefing up the ar5, I think antonio (Sky888) is your best bet.

[SKY888]

So as I post a while back my synchro gears for 2nd are gone in my trans and well I decided to go with a junkyard used one for now. I haven't bought it yet but will be soon unless someone here has a better solution for me. Not sure but if anyone has rebuild the ar5 trans can you please let me know how involved it really is. Also I'm looking at doing a big hp build for my solstice in the 400-450 whp range and would like to build up the trans Im taking out is I can install it with the rebuilt engine. With that being said what are the off the self options to beef up the ar5.

I had a similar experience a year or so ago.

both the 2nd and 3rd gear synchros were messed up.

When we drained the oil, you can see metal shavings.

I'm not really confident to have SMG rebuild it for me....and the local transmission shops.


With the cost to rebuild a tranny, I think it will be very comparable to just buying a used one.

Try contacting both WERKS and DDM if they have a fresh or low mileage tranny up for sale.  Or your local junkyard if they have one.

I was able to buy a 2000 mile tranny from Werks which was in a very reasonable price.

I was contemplating to use the synchros of the hummer which somebody told me were very similar to ours.   They are carbon fiber and stronger.

But I ended up just sending my tranny to be cryo-treated.

I'll try this cryo-treated unit out first....and see how it holds up.    If it gets destroyed..........I'll try a T-56 transmission  next

[Critterman]

Another option if Werks and DDM don't have one is Wade's Garage who is not a supporting vendor so you will have to look him up on the internet.

[hammy221]

Well after shopping for a transmission at ddm and wade's with no luck I shot werks an email and sure enough they had on for a price I couLdnt pass up so I bought it. Dave at werks said it will be shipped tomorrow and it has low mileage on it under15k. So cross our fingers and hope it gets here fast.

[Bill Hahn Jr]

In extensive drag racing use, where fast shifts are a necessity, we've seen a shortcoming in the 3-4 shift fork.  I recommend that during any rebuild or repair this fork be closely scrutinized for cracks, if not simply replaced as a matter of course.

In the interest of economy of production, the 3-4 fork is a cast aluminum piece, making it much less durable than the 1-2 fork, which instead features forged aluminum construction.  It appears the designers of the transmission figured people might be harder on the 1-2 shifts than the 3-4.  Said designers apparently don't know us drag racers!

I offer this information as advice to anyone rebuilding this transmission.

[hammy221]

Bill thank you for the advice.  Now not knowing much about transmissions but lots of mechanical knowledge I understand what you saying but my question is can you symply us a 1-2 fork in place of the 3-4 or are they different and also if different anyone know where you can get a forged one by chance.

[Bill Hahn Jr]

Bill thank you for the advice.  Now not knowing much about transmissions but lots of mechanical knowledge I understand what you saying but my question is can you simply use a 1-2 fork in place of the 3-4 or are they different and also if different anyone know where you can get a forged one by chance.

You're welcome 

Unfortunately, they are in fact different configurations, and not interchangeable.  I don't know if a forged 3-4 alternative exists, but we have considered building a billet replacement piece, should the potential demand prove sufficient.

[SKY888]

Well after shopping for a transmission at ddm and wade's with no luck I shot werks an email and sure enough they had on for a price I couLdnt pass up so I bought it. Dave at werks said it will be shipped tomorrow and it has low mileage on it under15k. So cross our fingers and hope it gets here fast.

I'm glad WERKS was able to help you out and have one unit available!

good luck bro!

[SKY888]

You're welcome 

Unfortunately, they are in fact different configurations, and not interchangeable.  I don't know if a forged 3-4 alternative exists, but we have considered building a billet replacement piece, should the potential demand prove sufficient.

Bill, put me on the list! 

[Bill Hahn Jr]

Will do, Antonio.  Thanks for your interest, good luck with the new build!

[Gentleman Jack]

Hey Werks

The transmission you sold to Hammy.... It had 15000 miles or 15000 trips down the drag strip?  Synchro mesh 3-4 mashed potatoes!!!!!

Kidding!   Just kidding!!!!

[miller11386]

15,000 times down the drag strip would be under 11k miles, figuring a 1/4 track and another 1/2 mile to pre-stage, shutdown and return to the pits.

[Gentleman Jack]

Wow.  Cause there's no way they drive the car to or from the track either right?  So technical Miller......  Did you go to Maths school?

[miller11386]