This good price for 18sp?

Is your 15 a double over ? What rear end do you have

 

Your running the same setup I have now with a 475 cat. I'm going back to 24 talls this weekend. With the lp's I actually shift less than I do with the talls. With the talls I do fine in the big hole when empty and just anticipate the hills and drop a gear when loaded. I run 90,000 loaded so I obviously don't run the interstate.

 

bull hauler you have the same trans that I had. The deep reduction is nice but I never really used it. I also I have 3.55 rears only difference is I have tall rubber. You will like the new style trans. Its a good setup for the older trucks we have. The final drive on your trans now is like .79 the 18spd or 13spd will be .73. which is a good difference on the highway I run 70mph at 1415 rpm. But as I said b4 where I save my most fuel mileage is the difference between the shifts, a 18 or 13 puts the shifts closer together so I don't get caught between 14th and 15th when pulling. Let us know which way you go. but if your trans is still hanging in there wait a little bit and keep looking around for a good deal you can find them. Unfortunately, not everyone can wait to do a trans job especially when you need to have the truck back up and running. It took me approx. four months to do the job. Find a trans for good price, buy new clutch, then find time between runs to do the actual job. But so far I am very happy with the set-up. What year w-9 you have.

Peterbilt 359 1985 ext. hood 3406b 100% restoration 2 yrs ago.

 

I've got a soft spot for 15's but nowadays I'd go with the 18. I'd say go 13 to save a little but since you haul cattle it's probably nice to have a slow reverse for farms etc. The seems to be the going rate. They want your core because 15's are still popular for dump trucks and such.

 

Why not go with a 13spd for 1/2 the price??? There are several variations you can choose from and order the gearing you want.... just my .02

 

Ain't no way you would like a 13sp after having deep reduction. That's all I use loading and unloading.

I had a 13 in my T6 and when it gave out I stuck the 9sp back in it. The only thing we used the 13 for was splitting the top gear running 80-90,000. And it was hard on the clutch on the bottom end.

If your willing to shell out the money put the 18 in. You won't be sorry at all!!!!

Just make sure you understand how to drive it or you will be rebuilding the back box.

 

With 3.55 rears you will not have a problem in reverse with the 13/18 spd. I was worried about losing my deep reduction in reverse but it really doesn't factor in. The only time guys have had problems is when they put higher rears in. That's when loaded inclines create hopping and clutch wear, but with your set-up you will do just fine. Like hurricane69 has said you really won't be sorry with the 18. How is your clutch and what style do you have in there? You may want to switch that when you do the job since your right there. I put an easy throw clutch in when I did the swap and it has made a nice difference on my knee, but I had the old style clutch you prolly already have the new style in your rig.