Diff locker? or 4wd actuator? (pics)

**cottonfarmer** · 04-14-2008, 09:03 PM

ok on my 92 hijet jumbo cab, is this a diff lock that is vaccum operated, or is it a 4wd actuator. its bolted onto the righthand side of the differential and the right hand cv shaft comes out of it to the wheel. When you depress the 4wd drive switch it engages, when you shift the transfer into low range it engages automatically also. have not checked to see if it disengages in certain gears or not. this is on a 92 or 93 daihatsu jumbo cab.

Hey also heres a pic of the rear u-joint part number off the napa box, they had it in stock. the part number is 410 in case you cant see it on the box.
Dave

p.s. My 97 jumbo cab daihatsu does not have this type of actuator on it? why is that?

**greg0187** · 04-14-2008, 09:16 PM

Hi Dave,
Its more of a 4WD actuator. It engages the front diff when you are in 4WD. Similar to the result of manually locking hubs. I believe it should should stay engaged as long as you are in 4WD no matter what gear you are in. Thanks for the part # on the U-joint. Any problems removing the old ones? On mine it doesn't have any c-clips to hold the U-joint in place, the yoke casting just has some impressions that hold the joint in place after it was installed at the factory.

-Greg

**cottonfarmer** · 04-14-2008, 10:17 PM

MY 97, JUMBO HIJET DOES NOT HAVE THE VACCUM CONTROLE ON THE FRONT DIFF LIKE THE ONE PICTURED ABOVE. why IS THAT?, DIFFERENT TRANNNY? SHIFTS IN THE TRANSFERCASE?

so on my 93 does the front driveshaft turn all the time?

**greg0187** · 04-15-2008, 05:08 AM

My 99 does not have one like that either. It does however have one internal to the differential casing (there are two vacuum lines going to it). I tested it out and it just engages the diff.

-Greg

**DRW** · 04-15-2008, 07:43 AM

What you are describing sounds like an axle disconnect system which is what GM has used on it's 4WD systems since about 1989.

**myhijet** · 04-15-2008, 08:57 PM

From what I gather on my 97 hijet, the front drove shaft turns when the rear drive shaft turns. No 2 wheel to 4 wheel shifting in the transfer case like us pickups. 2 wheel to 4 wheel is done by a sleeve collar on the front diff that engages the right axle half to the diff at the diff.

**greg0187** · 04-15-2008, 10:36 PM

They must have changed it after b/c the my front shaft does not turn unless its in 4WD. The front driveshaft is engaged by vacuum lines on the transfer case.

-Greg

**woodsrat** · 04-16-2008, 03:23 PM

My 93 Hijet has that very same set-up as the pictures, Some times I have to push the
4x4 button a few times to get it to engage. Is this normal for the Hijet's? Thanks for the u-joint numbers!

**volkswagen50** · 04-16-2008, 04:28 PM

Sometimes my 4x4 takes a little forward movement to engage the gears. I think it's normal.

**TRAX and HORNS** · 04-19-2008, 10:15 AM

Guys, check your vaccum hoses close going to front diff. The age of these trucks create small cracks in hoses mainly were hose is at a 90 degree turn. I have had a couple of trucks that would not go into 4x4 because of very small cracks in vacuum lines. One truck would go in and out of 4x4. Sometimes it would get vacuum and sometimes no vacuum. Doesnt take much of a leak. I bought 20' of vacuum line at local parts store. Cheers.

**10canmini** · 09-13-2009, 06:39 PM

hey guys having similar problem. my rear diff vac can always works but the front is very moody. sometimes it tries to engage but won't. sometimes it works great. i replaced all hoses for front vac can today but still no real difference. any other suggestions if rear can always works but front doesn't?? thanks 10canmini

**mitz65** · 09-16-2009, 07:23 PM

Originally Posted by woodsrat

My 93 Hijet has that very same set-up as the pictures, Some times I have to push the
4x4 button a few times to get it to engage. Is this normal for the Hijet's? Thanks for the u-joint numbers!

hi mine does the same, sometimes it just clicks off, and engages only sometimes. any answers

**10canmini** · 09-16-2009, 08:55 PM

after testing front vac diaphram(was working) i replaced all hoses involved with front diff vac diaphram. i then began testing actuaters and found not always getting 12 volts to actuater responsible for front diff. electrical was my problem so make sure you check electrical and not just vacuum.
good luck