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The T-56 is a proven alternative. I would not normally change to one, but if the alternative is having a rebuild done it may be worthwhile.

You might also look at a replacement AR5.

I still don't understand how a synchro can cause motion when engaging a gear at stand-still.
 

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I still don't understand how a synchro can cause motion when engaging a gear at stand-still.
I found this on another forum that seems to explain it:

When you are off the clutch in neutral, the input shaft of the trasmission is spinning with the engine, while the output shaft is not, since it's connected to the road. The gears connect the input and output shaft together.

When you push the clutch in and shift into first, the synro has to match the speed of the input shaft (~800rpm) to the speed of the output shaft (0rpm). This can cause the car to lurch forward just a tiny bit, while the syncro slows the input shaft to 0rpm so the gear can fully engage. Since the syncro is connected to the gear, this will put just a tiny bit of torque through to the output shaft. The reason it doesn't happen again if you keep the clutch in, then go to neutral then back to first is because the input and output shaft are already matched.

Have none of you really noticed this? Go out and try it. Start your car, put it in neutral. Then let the clutch out, clutch back in and put it into first gear really fast. The car will lurch forward just a tiny bit. It's normal and isn't a problem.
 

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Just saw an AR5 on Ebay for $800 used. I don't think that you will find a T-56 or any of the Tremec transmissions for anything close to this price. I'm a little surprised that the LS conversions stayed with the AR5 but I guess that it works even though I don't think that GM put this trans on any LS motors. You may find a good used T-56 but I have yet to see one under $2400.
 

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Just saw an AR5 on Ebay for $800 used. I don't think that you will find a T-56 or any of the Tremec transmissions for anything close to this price. I'm a little surprised that the LS conversions stayed with the AR5 but I guess that it works even though I don't think that GM put this trans on any LS motors. You may find a good used T-56 but I have yet to see one under $2400.
right, but as far as I know.. the r154 supra transmission is a fairly simple swap with an LS motor... which is probably why it works with our AR5. Which also means, I would look and see if people are doing r154's behind LS motor (which I am fairly sure is a decently used swap option for LS powered anything). There are options but they are $$$. Fast, cheap, reliable - you only get to pick two.
 

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apparently also the cd0009 transmission from 350z/g35 is the hot ticket to throw behind an LS motor right now, according to one of my drift buddies, those guys put an LS motor in everything, coupled to everything.
 

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Discussion Starter #26
I found this on another forum that seems to explain it:

When you are off the clutch in neutral, the input shaft of the trasmission is spinning with the engine, while the output shaft is not, since it's connected to the road. The gears connect the input and output shaft together.

When you push the clutch in and shift into first, the synro has to match the speed of the input shaft (~800rpm) to the speed of the output shaft (0rpm). This can cause the car to lurch forward just a tiny bit, while the syncro slows the input shaft to 0rpm so the gear can fully engage. Since the syncro is connected to the gear, this will put just a tiny bit of torque through to the output shaft. The reason it doesn't happen again if you keep the clutch in, then go to neutral then back to first is because the input and output shaft are already matched.

Have none of you really noticed this? Go out and try it. Start your car, put it in neutral. Then let the clutch out, clutch back in and put it into first gear really fast. The car will lurch forward just a tiny bit. It's normal and isn't a problem.
That pretty well describes what I am feeling in my car, and if that were the only issue I had with the trans I would not worry about it, but as it has been getting worse, and combined with the shifting issues I am having I will have to do something about it this winter.
I tested my 2 other manual trans cars this weekend a 1969 Firebird with a stroked OHC-6 and T-5, and the 77 Astre Formula with a 215 Buick V8 and T-5, they both have 4.11 rear gears, the Firebird weighs 3600 lbs & the Astre weighs 2800 lbs, neither car does it. Nor can I remember any of my other 20 odd manual trans cars or trucks doing it.

After searching for upgrade options and talking to a few "experts" it looks like I will be changing the trans out this winter. Still in the early research stage so I don't have any definite plans as of yet, but Tremec is located close to me and they are willing to look at the car. So that may be the next step. I really do not want to go the 6 speed rought, but it does not look like a TKO 500 or 600 will fit without modifying the trans tunnel and or center chassis. I don't want to go there. So a Magnum 6 speed may be the way to go, but they are $3000 new, and would require a new Bell housing, Clutch, pressure plate, throw out bearing, shifter, rear mount, & drive shaft. That sounds like a easy $5000 bill just in parts. And I haven't priced anything else out yet.

But it is a proven trans that can handle the LS2's torque. And the T56 that it is derived from has been swapped in our cars before so there should be no suprises. I will look at a few other options mentioned as well. Thanks for the ideas, keep them coming. This as all my previous cars mods is starting to snowball. I should be used to it by now.
 

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LSX LS1 LS2 LS3 LS6 LS7 LS9 L98 Engine to 350Z 370Z VQ Transmission Compound Adapter Plate

with this adaptor you can use a 350z trans with your motor (there are other cheaper adaptors, but they require unique clutch solutions). That trans can be had for under 750 dollars used, and they are common to rebuild, and parts are available. So. Some options for you.

*edit* on another note.... if the LS motor can bolt to the AR5 transmission, then that means this adaptor could probably bolt the CD009 transmission to the LNF motor, opening up a six speed option to the rest of us.
 

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Discussion Starter #28
Now you have me thinking, I found a Brand new in the box 350Z trans near me for $1000.00 asking price, that adaptor plate is $450 but having to saw off the stock cast on bell housing makes me nervious! I am sure I could do it but still. So figuring in a used 98-2002 F-body bellhousing, clutch, pressure plate, slave cylinder, driveshaft, X-member with mount, and what to do about the shifter. I could probably get it installed for around $3500.00 all in.

The new Tremec magnum 6-speed alone is around $3200.00 plus all the other parts would probably run close to $6000.00 all in. I may have to find a manual trans 350Z to test drive this weekend to see if I like the way the trans shifts. Hmmmmm
 

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Now you have me thinking, I found a Brand new in the box 350Z trans near me for $1000.00 asking price, that adaptor plate is $450 but having to saw off the stock cast on bell housing makes me nervious! I am sure I could do it but still. So figuring in a used 98-2002 F-body bellhousing, clutch, pressure plate, slave cylinder, driveshaft, X-member with mount, and what to do about the shifter. I could probably get it installed for around $3500.00 all in.

The new Tremec magnum 6-speed alone is around $3200.00 plus all the other parts would probably run close to $6000.00 all in. I may have to find a manual trans 350Z to test drive this weekend to see if I like the way the trans shifts. Hmmmmm
See now you are cookin with gas! If the trans is near you, maybe you could go take some measurements and see where the shifter location ends up compared to the AR5 trans, and get some detailed photos. I personally would probably try and find the cheapest trans possible, and then just rebuild it. Since the bell housing needs to be cut off anyway, getting a new one would be kind of a waste. Butttttttttttt on the same token the piece of mind with a brand new trans would be much better!
 

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Discussion Starter #30
I may have figured out another option, I found the AR-5 Transmission is basically the same transmission that Toyota put in the Supra's and called a r154. There are a couple of companies that rebuild and upgrade r154's and advertise they can rebuild/upgrade your trans for $1300 plus shipping, plus the cost of any shaft, gear or case replacement required. They claim they can upgrade the r154 to withstand 500 lb ft or torque.

So if they will work on my AR-5 $1500 and no major modifications sound like a great deal to me. I will let you know what I find out.
 

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I may have figured out another option, I found the AR-5 Transmission is basically the same transmission that Toyota put in the Supra's and called a r154. There are a couple of companies that rebuild and upgrade r154's and advertise they can rebuild/upgrade your trans for $1300 plus shipping, plus the cost of any shaft, gear or case replacement required. They claim they can upgrade the r154 to withstand 500 lb ft or torque.

So if they will work on my AR-5 $1500 and no major modifications sound like a great deal to me. I will let you know what I find out.

Yeah I said that from the getgo ;)
 

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Discussion Starter #32
Reread your 2nd post and yes you did, sorry I forgot. But I must of sorta remembered as I did start looking up r154 info. One of the rebuilders did get back to me and they said they could do it, but it would be " a little" extra for some different than normal parts. They did not explain how much or what parts. Good to know there is an option to upgrade the stock transmission.
 

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Reread your 2nd post and yes you did, sorry I forgot. But I must of sorta remembered as I did start looking up r154 info. One of the rebuilders did get back to me and they said they could do it, but it would be " a little" extra for some different than normal parts. They did not explain how much or what parts. Good to know there is an option to upgrade the stock transmission.

Its allllll good! I am glad you found a place though! Please keep us updated on how it works out, I am interested to see what they do with your trans (and what shop if you could pm me)
 

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I found this on another forum that seems to explain it:

When you are off the clutch in neutral, the input shaft of the trasmission is spinning with the engine, while the output shaft is not, since it's connected to the road. The gears connect the input and output shaft together.

When you push the clutch in and shift into first, the synro has to match the speed of the input shaft (~800rpm) to the speed of the output shaft (0rpm). This can cause the car to lurch forward just a tiny bit, while the syncro slows the input shaft to 0rpm so the gear can fully engage. Since the syncro is connected to the gear, this will put just a tiny bit of torque through to the output shaft. The reason it doesn't happen again if you keep the clutch in, then go to neutral then back to first is because the input and output shaft are already matched.

Have none of you really noticed this? Go out and try it. Start your car, put it in neutral. Then let the clutch out, clutch back in and put it into first gear really fast. The car will lurch forward just a tiny bit. It's normal and isn't a problem.
I found this interesting, because I had never experienced it. This morning I got stuck in traffic on a dead-level section of road (pretty rare around here) so I had a chance to experiment. I ultimately figured out that I have never felt this because 1) I am usually not on dead-level road when starting out so 2) I pretty much never engage gear without the brake on and 3) you really do have to jam the transmission into gear very quickly, and I don't do that. I found that, if I was very quick with the gearshift I would get a very mild pull that moved the car perceptibly but not a lot. It felt most like someone leaning against the back and easing it forward. I suppose if the synchroniser was bad it would be more pronounced, but what I felt was nowhere near a lurch or jerk. If I counted "1" before shifting into gear I had to concentrate hard to feel anything, and after counting to "2" I didn't detect anything at all because the delay allowed the input shaft to stop rotating.

I don't think my little experiment proved much of anything, but it did amuse me for a few minutes.
 

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Discussion Starter #36
John, that is a better description than I wrote of that symptom, it was present when I 1st bought the car, but has been getting progressively worse. Still if that was the only issue I was having I would not be concerned about it. I never thought about my driving style with not having my foot on the brake when going from neutral to 1st gear making much of a difference, but I can believe it does.

Choptop thanks for the link, but that price for a used transmission with unknown miles is probably about what I would pay for the other company to rebuild/upgrade mine, plus the shipping both ways. But as always I appreciate the effert involved.
 

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John, that is a better description than I wrote of that symptom, it was present when I 1st bought the car, but has been getting progressively worse. Still if that was the only issue I was having I would not be concerned about it. I never thought about my driving style with not having my foot on the brake when going from neutral to 1st gear making much of a difference, but I can believe it does.

Choptop thanks for the link, but that price for a used transmission with unknown miles is probably about what I would pay for the other company to rebuild/upgrade mine, plus the shipping both ways. But as always I appreciate the effert involved.
Question: Sitting at idle you push in the clutch, select 1st gear, and lurch forward slightly. What happens if you then shift into neutral and back to first while holding the clutch in?
 

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Discussion Starter #39
Question: Sitting at idle you push in the clutch, select 1st gear, and lurch forward slightly. What happens if you then shift into neutral and back to first while holding the clutch in?
I don't think anything happens, but I will verify that this weekend. Its actually supposed to be very nice up here, and I actually have the entire weekend off.
 

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Discussion Starter #40
John,

Just some info on what you asked about taking it out of gear and putting it back into 1st after I experience the slight "bump" going from neutral into 1st. If I put it directly back into 1st after just a couple of seconds I don't feel the "bump" but if I wait around a minute or so the "bump" returns.

Still looking at options, probably will not decide what route to go until late next month. Still have some top down weather here in the Mitten.
 
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