Hot Rods T5 5th gear , can you change it.

Yes my apologies but spent the last few hours searching got close but no cigar.
We have a 1352 216 WC t5 from a 1993 2.2 s10 with the 26 spline input. so the numbers say. It has been inspected and has been fully rebuilt , but the fifth gear set gives us a .86 O/D which is lower than we need . We want to put in 3.78 or lower rear gears to suit our cam and tire size for our flathead in our 32 3W.
So to cut a long story short what parts are needed to convert this to an od in the .72 zone. Any major problems? And who is a good source for supply. Thanks.

 

According to the catalog you should have a 25 tooth 5th gear on the main shaft and a 51 tooth on the countershaft. There are 27/29/31/33 tooth main shaft gears and 53/55/59 tooth countershaft gears listed also. So it looks possible to change it but I don't know for sure. Don't know if they will physically fit.
List price is $310 for the gear set.

 

So who would be a good source of contact for parts?

 

I buy my stuff through Transtar. But I think they are wholesale only.

 

There are several T5 applications with the top gear ratio you are looking for. Here's the list. You should be able to buy a gear set according to this list. http://www.britishv8.org/articles/borg-warner-t5-id-tags.htm

 

Yes ,thanks have followed this t5 ID chart, ours is a 1352 216. So according to the chart should be .72 O/D so in fact the trans is .86 . No it's never been apart before, till this last week. A little disappointing that the numbers don't match what we hoped for on the tag.

 

Any of the gear sets will work on he mainshaft, as they are all splined the same. I don't know the best source for the gears sets, but you should be able to find something close to what you want

 

So am I correct in thinking that all we need are the two gears that make 5th gear set. Do these need to be world class gears or are all t5 gears the same.

 

Fifth is a totally separate gear set from 1-4. It can be changed, so long as you buy both drive and driven gears. I built a close-ratio box for a small six, with gears I found on eBay.

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Have spent some time surfing through the S10 mini truck site but no definitive ideas on exactly what number of the teeth we need on each gear or who to hit up for a supply .

 

The tooth count between the drive and driven gears in the 5th set are not the strict ratio, as there is a reduction between the two shafts in the main body of the transmission.

Fifth in a S10 box may have the same tooth count as 5th in a Camaro box, but a very different final output ratio.

I believe that your transmission has 37/21 main set, and 25/51 5th set.

37/21 x 25/51 = 0.86:1

To get final ratio you want, you need to change the 25/51 part of that equation to another available combo, and re-run the equation.

For reference sake, in a Camaro, that same 5th set would come out to: 31/24 x 25/51 = 0.63:1, because the main set is different.

 

Never heard of an .86 but not saying it can't be, double checked, yes? ..try.. fivespeeds.com....

 

0.86:1 is the 5th gear ratio of an S10 T5, with the 4.03:1 first gear set.

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Oh, and CHECK MY MATH. I am running from half-caffeinated memory, riding a city bus.

 

Your math is right on with tooth counts given..

 

Thanks a bunch very good start for a hunt for gears. But heck I certainly do not want a .63 overdrive the poor old flathead would sure struggle on New Zealand roads ,all hills and corners,well mostly.

 

For a mild flathead, I think that the 0.86:1 would be good.

I believe that your only option for this setup will put you at 0.72:1, and between 4th at 1.00:1 and 5th at 0.72:1, you will find a huge RPM drop that the flathead might not like.

Just so you know how I know, I have that exact RPM drop on a 110-hp 144-inch Falcon-6. It ain't happy. You really have to wring-out 4th, before heading for 5th.

I have a 0.86:1 gear set on the bench, to go in, when I have a moment.

In any case, for a 0.72:1 5th, look for the 5th gear set from a S10 T5, with the 3.76 gear set.

 

Thank for that reply. We have a reasonable flathead with an decent L100 cam etc. when we get to a town and back off at slow revs it over runs ( like when you are in too tall a gear, clunk clunk) have tried retarding timing but it doesn't like that. Sure we can change down earlier but it's a pain.
In 4th and a slow 3rd it clunks for want of a better word. But slight power or gentle drive it's ok. So the plan was to fit change from 3.54 rear gears ( yup we have 750 x16" also to compound the deal) to fit 4.11 gears and a taller o/d ratio.
Just did the math with the .72 O/D and with 3.78 gears it will drop 750 rpm at 60 mph 4th to 5th making 2000 rpm at 60
4.11 gears it will drop 850rpm at 60 mph 4th to 5th. Making 2166rpm at 60mph
With my present set up it should drop 375 rpm but the tach. Says only 200.
So could my plan be flawed?

 

I will plug the numbers into my spreadsheet when I get home. That will show the speeds at various RPM's, in each gears.

Hard to say, without some hard data. My 7.50 x 16's are 31" tall, on my A, so I will use that in the equation.

 

I believe they DO need to be world class. I understood that all parts from a WC unit, will only interchange with other WC units.

 

Check out the RPM drops between 4th and 5th:

 

With the 0.72:1 5th, whatever RPM you are at when you shift, it will drop by about 1000 RPM when you go into 5th.

With the 0.86:1 5th, whatever RPM you are at when you shift, it will drop by about 500 RPM when you go into 5th.