4-Tec Tra4840 Proball diffs,Pros,and cons?

[jamsmanblue508]

I just bought a set of used proball diffs. on ebay for $50.00. I had a question, will these give you more speed? and was is the pros of haveing these in your car? I only bought them cause they were cheep, and it looks like they were never even installed in the kids car. and there Chrome, and most of the parts on my car are chrome.

[slowenuff]

First I just wanna be sure you have an electric 4tec and not a nitro 4tec. As to your first question no they wont really add any speed. As far as understanding the pros you have to understand the weakness's of the E 4tec. The stock differentials in the 4tec are adjustable ball diffs. Because of the materials they are made out of they wear out very very fast when used with a strong brushed motor or brushless system. The pro ball diffs are much stronger and should have no problem handling a powerful brushless system. And as far as cheap it depends on what you got for $50. Retail on pro ball diffs is about $50 to do the front or rear of the car. If you got a set to replace both the front and rear you got a good deal. The other reason for the pro ball diff is the ability to set up your handling the way you want.

[jamsmanblue508]

I got a 3.3 4-tec, and yes i paid $50.00 for both front, and rear.

You said you wanted to make sure i have and e 4tec,Why? they will work on the nitro,Right? I hope!

[slowenuff]

Yeah but this is forum for electric 4tec.

[jamsmanblue508]

Ooop's sorry!

[zero-x]

it has a different amount of teeth then the nitro ones. make sure you have adjustments to be able to compensate for the different number of teeth. i wouldn't use them if it was me. electric guys put nitro ones in cause the ball diffs don't hold up when going to brushless. so i don't see them holding up to a nitro engine.

[slowenuff]

You are mistaken zero. The "pro ball" diffs are a direct replacement/upgrade for the "nitro" 4tec. We electric guys use the stock diffs from the nitro 4tec because it's much cheaper than buying the pro ball diffs. The pro ball diffs have 34 teeth the same amount as the stock nitro 4tec diffs.

[zero-x]

ahh gottcha sorry

[slowenuff]

Nothin to be sorry about.

[jamsmanblue508]

Thanks guys! I did receive them a few days ago. Its weard cause one of the diff didn't have the holes drilled out in the part that holds the drive shafts on. The person said that traxxas sometimes puts the hole, and sometimes they don't. Have you ever heard of anything like that?

[slowenuff]

Can you post a picture?

[jamsmanblue508]

I've been trying and don.t know how to upload a pic on this form



This is the only way i could think of for you to see what i am talking about. Theres no holes drilled out of them. Click the link, and you'll see what i mean.

[cooleocool]

The ones without the holes are older. The older ones were held on with two grub (set) screws and one small machine screw in the middle. The newer ones with the holes were held on with the single set screw pin.

[slowenuff]

Since they are the older ones I would recommend using steel drive yokes since you will have to use grub screws.

[jamsmanblue508]

Yeh, the problem is i just bought a set of MIP steel cvds( for alot of money), and need to some how get the holes in these things. The problem is what size bit would i use?

[cooleocool]

You have to use the set screw/pins with the CVDs? When I installed CVDs on a Stampede back before the newer diff outputs, the kit from MIP included new grub screws (two for each output) and two new machine screws. I realize that wasn't on a 4-Tec, but one would think that it would be similar across the board from the same manufacturer.

[jamsmanblue508]

yeh, your right, thanks. everythings cool now. Thanks for the help

[cooleocool]

You're welcome. Glad you were able to put it together!